Vertex (VERX) 10-Q12 Aug 212021 Q2 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2021	Aug. 09, 2021
Document Information:
Document Type	10-Q
Document Period End Date	Jun. 30, 2021
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-39413
Entity Registrant Name	Vertex, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	23-2081753
Entity Address, Address Line One	2301 Renaissance Blvd
Entity Address, City or Town	King of Prussia
Entity Address State Or Province	PA
Entity Address, Postal Zip Code	19406
City Area Code	800
Local Phone Number	355-3500
Title of 12(b) Security	Class A Common Stock, Par Value $0.001 Per Share
Trading Symbol	VERX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Central Index Key	0001806837
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false
Class A
Document Information:
Entity Common Stock, Shares Outstanding		39,963,083
Class B
Document Information:
Entity Common Stock, Shares Outstanding		108,017,000

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 101,593	$ 303,051
Funds held for customers	31,060	9,222
Accounts receivable, net of allowance of $9,399, and $8,592, respectively	73,130	77,159
Prepaid expenses and other current assets	17,593	13,259
Total current assets	223,376	402,691
Property and equipment, net of accumulated depreciation	61,611	56,557
Capitalized software, net of accumulated amortization	34,364	31,989
Goodwill and other intangible assets	220,818	18,711
Deferred commissions	11,545	11,743
Deferred income tax asset	32,573	29,974
Operating lease right-of-use assets	22,156
Other assets	3,086	3,263
Total assets	609,529	554,928
Current liabilities:
Accounts payable	11,694	8,876
Accrued expenses	19,974	19,176
Distributions payable		2,700
Customer funds obligations	31,462	9,235
Accrued salaries and benefits	22,994	17,326
Accrued and deferred compensation, current	15,648	24,429
Deferred revenue	210,587	207,560
Current portion of long-term debt		882
Current portion of operating lease liabilities	3,641
Current portion of finance lease liabilities	271
Deferred rent and other		939
Purchase commitment and contingent consideration liabilities, current	10,458	845
Total current liabilities	326,729	291,968
Deferred compensation, net of current portion	4,244	5,010
Deferred revenue, net of current portion	12,025	14,702
Debt, net of current portion		225
Operating lease liabilities, net of current portion	26,726
Finance lease liabilities, net of current portion	334
Purchase commitment and contingent consideration liabilities, net of current portion	11,610	8,905
Deferred other liabilities	17	8,632
Total liabilities	381,685	329,442
Commitments and contingencies (Note 13)
Stockholders' equity:
Preferred shares, $0.001 par value, 30,000 shares authorized; no shares issued and outstanding
Additional paid in capital	209,629	206,541
Retained earnings	25,530	21,926
Accumulated other comprehensive loss	(7,463)	(3,127)
Total stockholders' equity	227,844	225,486
Total liabilities and stockholders' equity	609,529	554,928
Class A
Stockholders' equity:
Common stock, value issued	40	26
Class B
Stockholders' equity:
Common stock, value issued	$ 108	$ 120

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Allowance for accounts receivable	$ 9,399	$ 8,592
Preferred stock par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	30,000	30,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	300,000	300,000
Common stock, shares issued (in shares)	39,828	26,327
Common stock, shares outstanding (in shares)	39,828	26,327
Class B
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	150,000	150,000
Common stock, shares issued (in shares)	108,017	120,117
Common stock, shares outstanding (in shares)	108,017	120,117

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Revenues	$ 104,938	$ 91,271	$ 203,174	$ 180,516
Cost of revenues:
Cost of revenues	37,379	41,745	74,312	81,207
Gross profit	67,559	49,526	128,862	99,309
Operating expenses:
Research and development	11,926	13,617	23,385	26,696
Selling and marketing	24,865	24,544	45,015	48,877
General and administrative	24,865	37,758	49,717	75,394
Depreciation and amortization	2,878	2,505	5,705	5,374
Other operating expense, net	4,483	103	4,354	214
Total operating expenses	69,017	78,527	128,176	156,555
Income (loss) from operations	(1,458)	(29,001)	686	(57,246)
Interest (income) expense, net	(385)	1,059	150	1,628
Income (loss) before income taxes	(1,073)	(30,060)	536	(58,874)
Income tax benefit	(1,881)	(985)	(2,560)	(735)
Net income (loss)	808	(29,075)	3,096	(58,139)
Other comprehensive loss from foreign currency translation adjustments and revaluations, net of tax	3,359	276	4,336	3,274
Total comprehensive loss	(2,551)	(29,351)	(1,240)	(61,413)
Software subscriptions
Revenues:
Revenues	89,604	77,306	172,884	153,066
Cost of revenues:
Cost of revenues	26,829	26,001	52,419	50,685
Services
Revenues:
Revenues	15,334	13,965	30,290	27,450
Cost of revenues:
Cost of revenues	10,550	15,744	21,893	30,522
Class A
Operating expenses:
Net income (loss) attributable to stockholders, basic	$ 190	$ (32)	$ 644	$ (16)
Net income (loss) per share, basic (in dollars per share)	$ 0.01	$ (0.24)	$ 0.02	$ (0.24)
Weighted average common stock, basic (in shares)	34,726	132	30,592	66
Net income (loss) attributable to stockholders, diluted	$ 229	$ (32)	$ 811	$ (16)
Net income (loss) per share, diluted (in dollars per share)	$ 0.01	$ (0.24)	$ 0.02	$ (0.24)
Weighted average common stock, diluted (in shares)	44,711	132	41,357	66
Class B
Operating expenses:
Net income (loss) attributable to stockholders, basic	$ 618	$ (29,043)	$ 2,452	$ (58,123)
Net income (loss) per share, basic (in dollars per share)	$ 0.01	$ (0.24)	$ 0.02	$ (0.48)
Weighted average common stock, basic (in shares)	112,804	120,417	116,460	120,417
Net income (loss) attributable to stockholders, diluted	$ 579	$ (29,043)	$ 2,285	$ (58,123)
Net income (loss) per share, diluted (in dollars per share)	$ 0.01	$ (0.24)	$ 0.02	$ (0.48)
Weighted average common stock, diluted (in shares)	112,804	120,417	116,460	120,417

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Common StockFormer Class A	Common StockFormer Class B	Common StockClass A	Common StockClass B	Additional paid in capital.	Retained Earnings (Accumulated Deficit).ASC 842	Retained Earnings (Accumulated Deficit).	Accumulated Other Comprehensive Loss	Treasury stock	Former Class A	Former Class B	Class A	Class B	Options for redeemable shares	ASC 842	Total
Balance at Dec. 31, 2019		$ 54					$ (90,701)	$ (491)	$ (38,638)							$ (129,776)
Balance (in shares) at Dec. 31, 2019	147	120,270							41,910
Options for redeemable shares, bgn at Dec. 31, 2019														$ 17,344
Remeasurement of options for redeemable shares							(15,242)									(15,242)
Remeasurement of options for redeemable shares														15,242
Distributions declared							(4,010)									(4,010)
Foreign currency translation adjustments and revaluations, net of tax								(2,998)								(2,998)
Net income (loss)							(29,064)									(29,064)
Balance at Mar. 31, 2020		$ 54					(139,017)	(3,489)	$ (38,638)							(181,090)
Balance (in shares) at Mar. 31, 2020	147	120,270							41,910
Options for redeemable shares, ending at Mar. 31, 2020														32,586
Balance at Dec. 31, 2019		$ 54					(90,701)	(491)	$ (38,638)							(129,776)
Balance (in shares) at Dec. 31, 2019	147	120,270							41,910
Options for redeemable shares, bgn at Dec. 31, 2019														17,344
Foreign currency translation adjustments and revaluations, net of tax																(3,274)
Net income (loss)																(58,139)
Balance at Jun. 30, 2020		$ 54					(305,861)	(3,765)	$ (38,638)							(348,210)
Balance (in shares) at Jun. 30, 2020	147	120,443							41,910	147	120,443
Options for redeemable shares, ending at Jun. 30, 2020														47,223
Balance at Mar. 31, 2020		$ 54					(139,017)	(3,489)	$ (38,638)							(181,090)
Balance (in shares) at Mar. 31, 2020	147	120,270							41,910
Options for redeemable shares, bgn at Mar. 31, 2020														32,586
Remeasurement of options for redeemable shares							(14,637)									(14,637)
Remeasurement of options for redeemable shares														14,637
Distributions declared							(123,185)									(123,185)
Exercise of stock options, net							53									53
Exercise of stock options, net (in shares)		173
Foreign currency translation adjustments and revaluations, net of tax								(276)								(276)
Net income (loss)							(29,075)									(29,075)
Balance at Jun. 30, 2020		$ 54					(305,861)	(3,765)	$ (38,638)							(348,210)
Balance (in shares) at Jun. 30, 2020	147	120,443							41,910	147	120,443
Options for redeemable shares, ending at Jun. 30, 2020														$ 47,223
Balance at Dec. 31, 2020		$ 120	$ 26		$ 206,541		21,926	(3,127)								225,486
Balance (in shares) at Dec. 31, 2020			26,327	120,117								26,327	120,117
Exercise of stock options, net			$ 1		(6,998)											(6,997)
Exercise of stock options, net (in shares)			640
Shares issued upon vesting of Restricted Stock Awards					(34)											(34)
Shares issued upon vesting of Restricted Stock Awards (shares)			5
Stock-based compensation expense					6,302											6,302
Foreign currency translation adjustments and revaluations, net of tax								(977)								(977)
Net income (loss)							2,288									2,288
Balance at Mar. 31, 2021		120	$ 27		205,811	$ 508	24,722	(4,104)							$ 508	226,576
Balance (in shares) at Mar. 31, 2021			26,972	120,117
Balance at Dec. 31, 2020		120	$ 26		206,541		21,926	(3,127)								225,486
Balance (in shares) at Dec. 31, 2020			26,327	120,117								26,327	120,117
Foreign currency translation adjustments and revaluations, net of tax																(4,336)
Net income (loss)																3,096
Balance at Jun. 30, 2021		108	$ 40		209,629		25,530	(7,463)								227,844
Balance (in shares) at Jun. 30, 2021			39,828	108,017								39,828	108,017
Balance at Mar. 31, 2021		120	$ 27		205,811	$ 508	24,722	(4,104)							$ 508	226,576
Balance (in shares) at Mar. 31, 2021			26,972	120,117
Exercise of stock options, net			$ 1		(3,293)											(3,292)
Exercise of stock options, net (in shares)			462
Shares issued upon vesting of Restricted Stock Awards (shares)			234
Stock-based compensation expense					6,101											6,101
Shares issued under ESPP					1,010											1,010
Shares issued under ESPP (shares)			60
Class B shares exchanged for Class A shares		(12)	$ 12
Class B shares exchanged for Class A shares (shares)			12,100	(12,100)
Foreign currency translation adjustments and revaluations, net of tax								(3,359)								(3,359)
Net income (loss)							808									808
Balance at Jun. 30, 2021		$ 108	$ 40		$ 209,629		$ 25,530	$ (7,463)								$ 227,844
Balance (in shares) at Jun. 30, 2021			39,828	108,017								39,828	108,017

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ 3,096	$ (58,139)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	17,697	15,416
Provision for subscription cancellations and non-renewals, net of deferred allowance	994	154
Amortization of deferred financing costs	106	428
Stock-based compensation expense	12,828	76,596
Deferred income tax benefit	(2,812)	(1,057)
Non-cash operating lease costs	1,867
Other	66	14
Changes in operating assets and liabilities:
Accounts receivable	10,993	7,093
Advances to stockholders	(2)	53
Prepaid expenses and other current assets	(3,396)	(1,717)
Deferred commissions	198	807
Accounts payable	2,515	2,911
Accrued expenses	(5,707)	(1,481)
Accrued and deferred compensation	(8,301)	(10,804)
Deferred revenue	(1,220)	(7,353)
Operating lease liabilities	(2,532)
Other	75	(2,165)
Net cash provided by operating activities	26,465	20,756
Cash flows from investing activities:
Acquisition of business, net of cash acquired	(193,591)	(12,318)
Property and equipment additions	(15,888)	(10,565)
Capitalized software additions	(5,125)	(7,264)
Net cash used in investing activities	(214,604)	(30,147)
Cash flows from financing activities:
Net increase in customer funds obligations	22,227	2,622
Proceeds from line of credit		12,500
Principal payments on line of credit		(12,500)
Proceeds from long-term debt		175,000
Principal payments on long-term debt		(51,009)
Payments for deferred financing costs, net		(2,904)
Proceeds from purchases of stock under ESPP	1,010
Payments for taxes related to net share settlement of stock-based awards	(10,715)
Proceeds from exercise of stock options	391	52
Distributions to stockholders		(140,378)
Distributions under Tax Sharing Agreement	(2,700)
Payments for purchase commitment liability	(788)
Payments on finance lease liabilities	(685)
Net cash provided by (used in) financing activities	8,740	(16,617)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(221)	(204)
Net decrease in cash, cash equivalents and restricted cash	(179,620)	(26,212)
Cash, cash equivalents and restricted cash, beginning of period	312,273	83,495
Cash, cash equivalents and restricted cash, end of period	$ 132,653	$ 57,283

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2020
Reconciliation of cash, cash equivalents and restricted cash to the Condensed Consolidated Balance Sheets, end of period:
Cash and cash equivalents	$ 101,593	$ 47,295
Restricted cash-funds held for customers	31,060	9,988
Total cash, cash equivalents and restricted cash, end of period	$ 132,653	$ 57,283

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Jun. 30, 2021
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Nature of Business Vertex, Inc. (“Vertex”) and its direct and indirect wholly owned subsidiaries (collectively, the “Company”) operate as solutions providers of state, local and value added tax calculation, compliance and analytics, offering software products which are sold through software license and software as a service (“cloud”) subscriptions. The Company also provides implementation and training services in connection with its software license and cloud subscriptions, transaction tax returns outsourcing, and other tax-related services. The Company sells to customers located throughout the United States of America (“U.S.”) and internationally. Basis of Consolidation The condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”) and include the accounts of the Company. All intercompany transactions have been eliminated in consolidation. On May 12, 2021, the Company acquired 95% of the outstanding equity of EVAT Solutions Limited (“EVAT”) and its subsidiaries, doing business as Taxamo (collectively “Taxamo”), a cloud-based provider of tax and payment automation for global eCommerce and marketplaces. As the Company has a controlling interest in Taxamo, its accounts have been included in the condensed consolidated financial statements from the acquisition date. On January 7, 2020, the Company acquired a 60% controlling interest in Systax Sistemas Fiscais LTDA (“Systax”), a provider of Brazilian transaction tax content and software. Systax is considered a Variable Interest Entity (“VIE”) and its accounts have been included in the condensed consolidated financial statements from the acquisition date. Systax was determined to be a VIE as Vertex is the primary beneficiary of the equity interests in Systax and participates significantly in the variability in the fair value of Systax’s net assets. Unaudited Interim Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial information and include the accounts of the Company. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes for the year ended December 31, 2020, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 (the “2020 Annual Report”) filed with the SEC on March 15, 2021. The interim condensed consolidated balance sheet as of December 31, 2020 has been derived from audited financial statements included in the 2020 Annual Report. The accompanying interim condensed consolidated balance sheet as of June 30, 2021, the interim condensed consolidated statements of comprehensive loss and changes in equity (deficit) for the three and six months ended June 30, 2021 and 2020, and interim condensed consolidated statements of cash flows for the six months ended June 30, 2021 and 2020 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with that used to prepare the annual audited consolidated financial statements and include, in the opinion of management, all adjustments, consisting of normal and recurring items, necessary for the fair presentation of the condensed consolidated financial statements. The operating results for the three and six months ended June 30, 2021 are not necessarily indicative of the results expected for the full year ending December 31, 2021. Segments The Company operates its business as one operating segment. For the three and six months ended June 30, 2021 approximately 7% and 6%, respectively, of the Company’s revenues were generated outside the U.S. For the three and six months ended June 30, 2020, revenues generated outside of the U.S. were approximately 3% in each respective period. Fair Value Measurement Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at a measurement date. A three-level fair value hierarchy (the “Fair Value Hierarchy”) prioritizes the inputs used to measure fair value. The Fair Value Hierarchy requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs. Classification in the Fair Value Hierarchy is based on the lowest of the following levels that is significant to the measurement: Level 1 Level 2 Level 3 The Company’s assessment of the significance of an input to a fair value measurement requires judgment, which may affect the determination of fair value and the measurement’s classification within the Fair Value Hierarchy. Use of Estimates The preparation of condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses during the reporting period. Significant estimates used in preparing these condensed consolidated financial statements include: (i) the estimated allowance for subscription cancellations, (ii) expected credit losses associated with the allowance for doubtful accounts; (iii) the reserve for self-insurance, (iv) assumptions related to achievement of technological feasibility for software developed for sale, (v) product life cycles, (vi) estimated useful lives and potential impairment of long-lived assets, intangible assets, (vii) potential impairment of goodwill, (viii) determination of the fair value of tangible and intangible assets acquired, liabilities assumed and consideration transferred in acquisitions, (ix) amortization period of material rights and deferred commissions (x) valuation of the Company’s stock used to measure stock-based compensation awards, (xi) Black-Scholes-Merton option pricing model (“Black-Scholes model”) input assumptions used to determine the fair value of stock-based compensation awards, (xii) measurement of future purchase commitment and contingent consideration liabilities and (xiii) the potential outcome of future tax consequences of events that have been recognized in the condensed consolidated financial statements or tax returns. Actual results may differ from these estimates. Software Development Costs Internal-Use Software The Company follows Accounting Standard Codification (“ASC”) 350-40, Goodwill and Other, Internal-Use Software, 3 Software Developed for Sale The costs incurred for the development of computer software to be sold, leased, or otherwise marketed are capitalized in accordance with ASC 985-20, Costs of Software to be Sold, Leased or Marketed 3 Business Combinations Upon acquisition of a company, the Company determines if the transaction is a business combination, which is accounted for using the acquisition method of accounting. Under the acquisition method, once control is obtained of a business, the assets acquired, liabilities assumed, consideration transferred and amounts attributed to noncontrolling interests, are recorded at fair value. The Company uses its best estimates and assumptions to assign fair value to the tangible and intangible assets acquired, liabilities assumed, consideration transferred, and amounts attributed to noncontrolling interests at the acquisition date. One of the most significant estimates relates to the determination of the fair value of these amounts. The determination of the fair values is based on estimates and judgments made by management. The Company’s estimates of fair value are based upon assumptions it believes to be reasonable, but which are inherently uncertain and unpredictable. Measurement period adjustments to these values as of the acquisition date are reflected at the time identified, up through the conclusion of the measurement period, which is the time at which all information for determination of the values of assets acquired, liabilities assumed, consideration transferred and noncontrolling interests is received, and is not to exceed one year from the acquisition date (the “Measurement Period”). Thus the Company may record adjustments to the fair value of these tangible and intangible assets acquired, liabilities assumed, consideration transferred and noncontrolling interests, with the corresponding offset to goodwill during this Measurement Period. Additionally, uncertain tax positions and tax-related valuation allowances are initially recorded in connection with a business combination as of the acquisition date. The Company continues to collect information and reevaluate these estimates and assumptions periodically and record any adjustments to preliminary estimates to goodwill, provided the Company is within the Measurement Period, with any adjustments to amortization of new or previously recorded identifiable intangibles being recorded to the consolidated statements of comprehensive loss in the period in which they arise. In addition, if outside of the Measurement Period, any subsequent adjustments to the acquisition date fair values are reflected in the consolidated statements of comprehensive loss in the period in which they arise. Goodwill Goodwill represents the excess of the purchase price over the fair value of net tangible and intangible assets acquired in a business combination. The Company evaluates goodwill for impairment annually at October 1 and whenever events or circumstances make it more likely than not that impairment may have occurred. Stock-Based Compensation The Company’s Registration Statement on Form S-1 with the SEC was declared effective on July 28, 2020, resulting in the Class A shares being registered and available for trading on the NASDAQ exchange (the “Offering”). On the effective date of the Offering, the Company adopted the 2020 Incentive Award Plan (the “2020 Plan”) and the 2020 Employee Stock Purchase Plan (the “ESPP”), which provide for the award of stock appreciation rights (“SARs”), stock options (“options”), restricted stock awards (“RSAs”), restricted stock units (“RSUs”), and participation in the ESPP (collectively, the "awards"). The awards are subject to, and the Company applies, the guidance set forth in ASC 718, Compensation—Stock Compensation, ("ASC 718") for the award of equity-based instruments. The provisions of ASC 718 require a company to measure the fair value of stock-based compensation as of the grant date of the award. Stock-based compensation expense reflects the cost of employee services received in exchange for the awards. SARs are accounted for as liabilities under ASC 718 and, as such, the Company recognizes stock-based compensation expense by remeasuring the value of the SARs at the end of each reporting period and accruing the portion of the requisite service rendered at that date. Prior to July 2, 2020, the date management determined the Company was considered to have become a public entity, the Company measured SARs at their intrinsic value. After such date, management remeasured outstanding SARs using the fair value-based method under ASC 718. Stock-based compensation expense for stock options issued under the 2020 Plan after the Offering is measured based on the grant date fair value of the award and is estimated using the Black-Scholes model. Compensation cost is recognized on a straight-line basis over the requisite service or performance period associated with the award. Stock-based compensation expense for RSAs and RSUs is based on the fair value of the Company’s underlying common stock on the date of grant. Compensation cost is recognized on a straight-line basis over the requisite service or performance period associated with the award. Stock-based compensation expense for awards subject to performance-based measurement criteria is recognized when achievement of performance targets is deemed probable. The ESPP permits participants to purchase Class A common stock through payroll deductions, up to a specified percentage of their eligible compensation or a lump sum contribution amount for the initial offering period. The plan is a compensatory plan as it allows participants to purchase stock at a 15% discount from the lower of the fair value of the Class A common on the first or last day of the ESPP offering period (the “ESPP Discount”).The ESPP is accounted for as an equity classified award. Stock-based compensation expense for the ESPP is measured based on the fair value of the ESPP award at the start of the offering period. The fair value is comprised of the value of the ESPP Discount and the value associated with the variability in the Class A common stock price during the offering period (the “Call/Put”), which is estimated using the Black-Scholes model. Compensation cost is recognized on a straight-line basis over the respective offering period. The Company has elected to recognize award forfeitures as they occur. Revenue Recognition Revenue from contracts with customers The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers Nature of goods and services Licenses for on-premise software subscriptions provide the customer with a right to use the software as it exists when made available to the customer. Customers purchase a subscription to these licenses, which includes the related software and tax content updates (collectively “updates”) and product support. The updates and support, which are part of the subscription agreement, are essential to the continued utility of the software; therefore, the Company has determined the software and the related updates and support to be a single performance obligation. Accordingly, when on-premise software is licensed, the revenue associated with this combined performance obligation is recognized ratably over the license term as these subscriptions are provided for the duration of the license term. Revenue recognition begins on the later of the beginning of the subscription period or the date the software is made available to the customer to download. The Company’s on-premise software subscription prices in the initial subscription year are higher than standard renewal prices. The excess initial year price over the renewal price (“new sale premium”) is a material right that provides customers with the right to this reduced renewal price. The Company recognizes revenue associated with this material right over the estimated period of benefit to the customer, which is generally three years. Cloud-based subscriptions allow customers to use Company-hosted software over the contract period without taking possession of the software. The cloud-based offerings also include related updates and support. Cloud-based contracts consistently provide a benefit to the customer during the subscription period; thus, the associated revenue is recognized ratably over the related subscription period. Revenue recognition begins on the later of the beginning of the subscription period or the date the customer is provided access to the cloud-based solutions. Revenue from deliverable-based services is recognized as services are delivered. Revenue from fixed fee services is recognized as services are performed using the percentage of completion input method. The Company has elected the "right to invoice" practical expedient for revenue related to services that are billed on an hourly basis, which enables revenue to be recognized as the services are performed. The Company has determined that the methods applied to measuring its progress toward complete satisfaction of performance obligations recognized over time are a faithful depiction of the transfer of control of software subscriptions and services to customers. Significant Judgments Contracts with customers often include promises to transfer multiple products and services to a customer. Determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together may require significant judgment. Identification of the amortization periods of material rights and contract costs requires significant judgement by management. Payment terms Payment terms and conditions vary by contract, although the Company’s terms generally include a requirement of payment within 30-days. In instances where the timing of revenue recognition differs from the timing of payment, the Company has determined that its contracts do not include a significant financing component. The primary purpose of invoicing terms is to provide customers with simplified and predictable ways of purchasing products and services, not to receive financing from customers or to provide customers with financing. Cost of Revenues Cost of revenues, software subscriptions includes the direct cost to develop, host and distribute software products, the direct cost to provide customer support, and amortization of costs capitalized for software developed for sale and for internal-use software utilized for cloud-based subscriptions. Cost of revenues, services includes the direct costs of implementation, training, transaction tax returns outsourcing and other tax-related services. Reimbursable Costs Reimbursable costs passed through and invoiced to customers of the Company are recorded as services revenues with the associated expenses recorded as cost of revenues, services in the condensed consolidated statements of comprehensive loss. Income Taxes On July 27, 2020, the Company’s S-Corporation election (the “S Election”) was terminated by the Company’s stockholders in connection with the Offering. As a result, Vertex became taxable at the corporate level as a C-Corporation for U.S federal and state income tax purposes. In connection with the S Election termination, the Company entered into an agreement with the S-Corporation stockholders pursuant to which the Company has indemnified them for unpaid income tax liabilities and may be required to make future payments in material amounts to them attributable to incremental income taxes resulting from an adjustment to S-Corporation related taxable income (the “Tax Sharing Agreement”). In addition, the Tax Sharing Agreement indemnifies the S-Corporation stockholders for any interest, penalties, losses, costs or expenses arising out of any claim under the agreement. Correspondingly, the S-Corporation stockholders have indemnified the Company with respect to unpaid tax liabilities (including interest and penalties) attributable to a decrease in S-Corporation stockholders’ taxable income and a corresponding increase in our taxable income as a C-Corporation for any period. Prior to July 27, 2020, as Vertex was taxed as an S-Corporation for U.S. federal and certain states income tax purposes, net income or loss was allocated to and included on the income tax returns of the S-Corporation stockholders. Historically, the Company distributed amounts to the S-Corporation stockholders to satisfy their tax liabilities resulting from allocated net income or loss. Vertex was taxed at the corporate level in those states where the S-Corporation status was not recognized or where the state imposed a tax on an S-Corporation. Accordingly, the income tax provision or benefit was based on taxable income allocated to these states. In certain foreign jurisdictions, Vertex subsidiaries were taxed at the corporate level, and the income tax provision or benefit was based on taxable income sourced to these foreign jurisdictions. Supplemental Cash Flow Disclosures Supplemental cash flow disclosures are as follows for the respective periods: For the six months ended June 30, 2021 2020 (unaudited) Cash paid for interest $ 119 $ 1,360 Cash paid for income taxes, net of refunds $ 966 $ 490 Operating cash flows from operating leases $ 2,701 $ — Non-cash investing and financing activities: Purchase commitment and contingent consideration liabilities $ 12,736 $ 14,344 Remeasurement of options for redeemable shares $ — $ 29,879 Leased assets obtained in exchange for new finance lease liabilities $ 173 $ — Recently Issued Accounting Pronouncements As an "emerging growth company," the Jumpstart Our Business Startups Act (the “JOBS Act”) allows the Company to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. The Company has elected to delay adoption of certain new or revised accounting standards. As a result, the Company’s financial statements may not be comparable to the financial statements of issuers who are required to comply with the effective date for new or revised accounting standards that are applicable to public companies. Recently Adopted Accounting Pronouncements Leases In February 2016, the FASB issued ASU No. 2016-02, Leases The Company adopted ASU No. 2016-02 on January 1, 2021 using the modified retrospective transition method, which did not require the Company to adjust comparative periods. The Company’s lease assets and lease liabilities are recognized on the lease commencement date in an amount that represents the present value of future lease payments. The Company’s incremental borrowing rate, which is based on information available at the adoption date for existing leases and the commencement date for leases commencing after the adoption date, is used to determine the present value of lease payments. The Company elected the "package of three" practical expedients permitted under the transition guidance, which allows (i) a carry forward of the historical lease classification conclusions, (ii) management to assess whether a contract is or contains a lease, and (iii) the retention of initial direct costs for any leases that exist prior to adoption of the new standard. As a result of the adoption of ASC 842 on January 1, 2021, the Company recorded both operating lease right-of-use assets of $24,004 and operating lease liabilities of $32,562. An adjustment to retained earnings of $508, net of the deferred tax impact, was also recorded. The adoption of ASC 842 had an immaterial impact on the condensed consolidated statement of comprehensive loss for the three and six months ended June 30, 2021, and the condensed consolidated cash flow statement for the six months ended June 30, 2021. The adoption of this standard also resulted in a change in the naming convention for leases classified historically as capital leases. These leases are now referred to as finance leases within property and equipment, with corresponding short-term and long-term debt liabilities being presented as “Current portion of finance lease liabilities” and “Finance lease liabilities, net of current portion,” respectively. See Note 7 for further information. The Company does not recognize leases with an initial term less than one year (“short-term leases”) on its condensed consolidated balance sheets, and recognizes such lease payments in the condensed consolidated statements of comprehensive loss on a straight-line basis over the lease term. Leases with an option to extend the related lease term or terminate early are reflected in the lease term when it is reasonably certain that the Company will exercise such options. Credit Losses In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments Income Taxes In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, Risks and Uncertainties In March 2020, the World Health Organization declared the outbreak of coronavirus disease 2019 (“COVID-19”) to be a pandemic. The COVID-19 pandemic is continuing to have widespread, rapidly evolving and unpredictable impacts on global society, economies, financial markets and business practices. To protect the health and well-being of Company employees and customers, substantial modifications were made to employee travel policies, and our offices were closed, and remained closed through June 30, 2021, with employees directed to work from home. In addition, conferences and other marketing events were cancelled or shifted to virtual-only, and the Company continued to participate virtually through June 30, 2021. The COVID-19 pandemic has impacted, and may continue to impact, Company operations, including employees, customers and partners, and there is substantial uncertainty regarding the nature and degree of its continued effects over time. The Company did not experience any significant reductions in sales, revenues or collections through June 30, 2021 as a result of COVID-19. The uncertainty caused by the COVID-19 pandemic could, however, impact Company billings to new customers for the remainder of 2021, and may also negatively impact Company efforts to expand revenues from existing customers as they continue to evaluate certain long-term projects and budget constraints. In addition to the potential impact on sales, the Company may see delays in collections during 2021 as customers adjust their operating protocols to accommodate implementation of new criteria to protect the health and well-being of their employees and customers. However, these delays are not expected to materially impact the business, and thus the Company has not recorded additional credit losses associated with the allowance for doubtful accounts in connection with any delays. The Company believes it has ample liquidity and capital resources to continue to meet its operating needs and to service debt and other financial obligations. The extent to which the COVID-19 pandemic impacts the business going forward will depend on numerous evolving factors that cannot reliably be predicted, including the duration and scope of the pandemic; governmental, business, and individuals’ actions in response to the pandemic; and the impact on economic activity, including the possibility of recession or financial market instability. These factors may adversely impact consumer, business and government spending on technology as well as customers’ ability to pay for Company products and services on an ongoing basis. This uncertainty also affects management’s accounting estimates and assumptions, which could result in greater variability in a variety of areas that depend on these estimates and assumptions, including estimated allowance for subscription cancellations, product life cycles and estimated lives of long-lived assets. Reclassifications Certain amounts in the prior period financial statements have been reclassified to conform to the presentation of the current period financial statements. These reclassifications had no effect on previously reported comprehensive income or loss.

REVENUE RECOGNITION

REVENUE RECOGNITION	6 Months Ended
REVENUE RECOGNITION	Jun. 30, 2021
REVENUE RECOGNITION
REVENUE RECOGNITION	2. REVENUE RECOGNITION See Note 1 for a description of the Company’s revenue recognition accounting policy. Disaggregation of revenue The table reflects revenue by major source for the following periods: Three months ended Six months ended June 30, June 30, 2021 2020 2021 2020 (unaudited) (unaudited) Software subscriptions: Software licenses $ 57,525 $ 57,194 $ 113,875 $ 113,919 Cloud subscriptions 32,079 20,112 59,009 39,147 Software subscriptions 89,604 77,306 172,884 153,066 Services 15,334 13,965 30,290 27,450 Total revenues $ 104,938 $ 91,271 $ 203,174 $ 180,516 Contract balances Timing of revenue recognition may differ from the timing of invoicing customers. A receivable is recorded in the condensed consolidated balance sheets when customers are billed related to revenue to be collected and recognized for subscription agreements as there is an unconditional right to invoice and receive payment in the future related to these subscriptions. A receivable and related revenue may also be recorded in advance of billings to the extent services have been performed and the Company has a right under the contract to bill and collect for such performance. Subscription-based customers are generally invoiced annually at the beginning of each annual subscription period. Accounts receivable is presented net of an allowance for potentially uncollectible accounts and estimated cancellations of software license and cloud-based subscriptions (the “allowance”) of $9,399 and $8,592 at June 30, 2021 and December 31, 2020, respectively. The allowance represents future expected credit losses over the life of the receivables based on past experience, current information and forward-looking economic considerations. The beginning and ending balances of accounts receivable, net of allowance, are as follows: For the six months ended For the year ended June 30, 2021 December 31, 2020 (unaudited) Balance, beginning of period $ 77,159 $ 70,367 Balance, end of period 73,130 77,159 (Decrease) increase, net $ (4,029) $ 6,792 A contract liability is recorded as deferred revenue on the condensed consolidated balance sheets when customers are billed in advance of performance obligations being satisfied, and revenue is recognized after invoicing ratably over the subscription period or over the amortization period of material rights. Deferred revenue is reflected net of a related deferred allowance for subscription cancellations (the “deferred allowance”) of $6,267 and $6,432 at June 30, 2021 and December 31, 2020, respectively. The deferred allowance represents the portion of the allowance for subscription cancellations associated with deferred revenue. The beginning and ending balances of and changes to the allowance and the deferred allowance are as follows: For the three months ended June 30, 2021 2020 Balance Net Change Balance Net Change Allowance balance, April 1 $ (8,059) $ (7,476) Allowance balance, June 30 (9,399) (7,669) Change in allowance $ 1,340 $ 193 Deferred allowance balance, April 1 5,515 5,118 Deferred allowance balance, June 30 6,267 5,335 Change in deferred allowance (752) (217) Net amount charged to revenues $ 588 $ (24) For the six months ended June 30, 2021 2020 Balance Net Change Balance Net Change Allowance balance, January 1 $ (8,592) $ (7,515) Allowance balance, June 30 (9,399) (7,669) Change in allowance $ 807 $ 154 Deferred allowance balance, January 1 6,432 5,614 Deferred allowance balance, June 30 6,267 5,335 Change in deferred allowance 165 279 Net amount charged to revenues $ 972 $ 433 The portion of deferred revenue expected to be recognized in revenue beyond one year is included in deferred revenue, net of current portion in the condensed consolidated balance sheets. The tables provide information about the balances of and changes to deferred revenue for the following periods: As of June 30, As of December 31, 2021 2020 (unaudited) Balances: Deferred revenue, current $ 210,587 $ 207,560 Deferred revenue, non-current 12,025 14,702 Total deferred revenue $ 222,612 $ 222,262 For the three months ended For the six months ended June 30, June 30, 2021 2020 2021 2020 (unaudited) (unaudited) Changes to deferred revenue: Beginning balance $ 218,133 $ 201,484 $ 222,262 $ 205,791 Additional amounts deferred 109,417 88,224 203,524 173,162 Revenues recognized (104,938) (91,271) (203,174) (180,516) Ending balance $ 222,612 $ 198,437 $ 222,612 $ 198,437 Contract costs Deferred sales commissions earned by the Company’s sales force and certain sales incentive programs and vendor referral agreements are considered incremental and recoverable costs of obtaining a contract with a customer. An asset is recognized for these incremental contract costs and reflected as deferred commissions in the condensed consolidated balance sheets. These contract costs are amortized on a straight-line basis over a period consistent with the transfer of the associated product and services to the customer, which is generally three years. Amortization of these costs are included in selling and marketing expense in the condensed consolidated statements of comprehensive loss. The Company periodically reviews these contract assets to determine whether events or changes in circumstances have occurred that could impact the period of benefit of these assets. There were no impairment losses recorded for the periods presented. The table provides information about the changes to contract cost balances as of and for the following periods: For the three months ended For the six months ended June 30, June 30, 2021 2020 2021 2020 Deferred commissions: (unaudited) (unaudited) Beginning balance $ 11,693 $ 10,563 $ 11,743 $ 11,196 Additions 2,135 1,630 4,193 2,694 Amortization (2,283) (1,803) (4,391) (3,500) Ending balance $ 11,545 $ 10,390 $ 11,545 $ 10,390

BUSINESS COMBINATIONS

BUSINESS COMBINATIONS	6 Months Ended
BUSINESS COMBINATIONS	Jun. 30, 2021
BUSINESS COMBINATIONS
BUSINESS COMBINATIONS	3. BUSINESS COMBINATIONS Taxamo On May 12, 2021, the Company acquired 95% of the outstanding equity of EVAT and its wholly owned subsidiaries (collectively “Taxamo”), a cloud-based provider of tax and payment automation for global eCommerce and marketplaces. This acquisition supports the Company’s growth strategies across eCommerce platforms and marketplaces in Europe and North America. The preliminary purchase price for the Taxamo acquisition was $200,689 as of the acquisition date, consisting of (i) $190,153 of cash paid at closing, partially offset by $2,662 of Taxamo’s cash received in the acquisition resulting in net cash consideration at closing of $187,491, (ii) an acquisition holdback with an estimated fair value upon acquisition of $502, and (iii) an option to purchase from and an option for the remaining shareholder to sell, the remaining 5% of the outstanding equity of EVAT (the “Option”) at a fixed amount between August and December 2021 for an estimated fair value of $10,034. The Company recorded the estimated fair value of the Option payment amount in purchase commitment and contingent consideration liabilities, current on the condensed consolidated balance sheets. Cash consideration was funded by the Company from available cash on hand. The following table summarizes the preliminary purchase price for Taxamo: May 12, 2021 (unaudited) Cash paid to Taxamo sellers at closing $ 190,153 Fair value of acquisition holdbacks 502 Fair value of purchase commitment liability 10,034 Total $ 200,689 The Company’s accounting for the Taxamo acquisition is preliminary. The purchase price is subject to purchase price adjustments related to the final determination of Taxamo’s cash, net working capital, and taxes as of May 12, 2021. The Taxamo acquisition was accounted for as a business combination. The total preliminary purchase price was allocated to the net assets acquired based on management’s determination of their estimated fair values using available information as of the acquisition date. The excess of purchase consideration over the net assets acquired is recorded as goodwill, which primarily reflects the value of acquired technology, and the existence of intangible assets not recognized under U.S. GAAP such as the value of the assembled workforce and other market factors. The Company expects that goodwill associated with the Taxamo acquisition will not be deductible for tax purposes. The preliminary values recorded, which are reflected in the table below, will be adjusted during the Measurement Period as more detailed analyses are performed and further information becomes available regarding the fair values of these amounts on the acquisition date. The Company does not have a preliminary estimate of identifiable intangible assets as of June 30, 2021. A third-party expert has been engaged to assist in the valuation of identifiable intangible assets as part of the acquisition. Any subsequent adjustments to the preliminary values not associated with determination of their fair values on the acquisition date will be recorded in the condensed consolidated statements of comprehensive loss in the period in which the change is identified. Taxamo’s business and product offerings are being integrated into the Company's one operating segment. The following table presents the allocation of the purchase price to the assets acquired and liabilities assumed as recorded in the Company’s condensed consolidated balance sheet as of the acquisition date: May 12, 2021 (unaudited) Cash and cash equivalents $ 2,441 Funds held for customers 221 Accounts receivable 7,783 Prepaid expenses and other current assets 908 Property and equipment 46 Goodwill 201,580 Accounts payable (304) Accrued expenses (6,615) Accrued compensation (3,939) Deferred other income (1,432) Total $ 200,689 The transaction costs associated with the acquisition were $4,522 and were recorded in other operating expense, net for the three and six months ended June 30, 2021. The Company has included the financial results of Taxamo in the condensed consolidated statement of comprehensive loss from the date of acquisition. As the Taxamo acquisition did not have a material impact on the Company’s reported revenue or net income for the three and six months ended June 30, 2021, pro forma financial information has not been presented. Tellutax On January 25, 2021, the Company executed an Asset Purchase Agreement with Tellutax LLC, a Portland, Oregon-based edge computing technology startup (“Tellutax”), to acquire substantially all of Tellutax’s assets (the “Tellutax Acquisition”). Cash consideration paid for the acquisition was $6,100, funded through cash on hand, and serves to strengthen the Company’s technology roadmap and hybrid cloud strategy enabling it to better serve customers in an increasingly hyper-connected environment. The Tellutax Acquisition entitles the sellers to contingent consideration if sales targets are met during a period of time following the acquisition. The Tellutax Acquisition was accounted for as a business combination. The total purchase price was allocated to the net assets acquired based on management’s determination of their estimated fair values using available information as of the acquisition date. The excess of purchase consideration over the net assets acquired is recorded as goodwill, which primarily reflects the value of expected future synergies, the existence of intangible assets not recognized under U.S. GAAP such as the value of the assembled workforce and other market factors. The Company expects that goodwill associated with the Tellutax Acquisition will be deductible for tax purposes. The fair values of these amounts on the acquisition date, which are reflected in the table below, have been finalized. Any subsequent adjustments to these values will be recorded in the condensed consolidated statements of comprehensive loss in the period in which the change is identified. The purchase price for the Tellutax Acquisition includes cash paid at closing plus an estimated fair value of contingent consideration of $2,200 (the “Tellutax Contingent Consideration”) as of January 25, 2021. The following table presents the allocation of the purchase price recorded in the condensed consolidated balance sheet as of the acquisition date: January 25, 2021 (unaudited) Capitalized Software - Developed technology $ 3,600 Goodwill 4,700 Total $ 8,300 The Company has included the financial results of Tellutax in the condensed consolidated statement of comprehensive loss from the date of acquisition. As the Tellutax Acquisition did not have a material impact on the Company’s reported revenue or net income for the three and six months ended June 30, 2021, pro forma financial information has not been presented. The fair value of developed technology was valued using the multi-period excess earnings method, which is a variation of the income approach. This method estimates an intangible asset’s value based on the present value of the incremental after-tax cash flows attributable to the intangible asset. The significant assumptions used in the developed technology valuation included forecasted results and discount rate. The fair value of Tellutax Contingent Consideration is estimated using a Monte Carlo Simulation to compute the expected cash flows from earn-out payments specified in the purchase agreement. The Tellutax Contingent Consideration is based on three potential earn-out payments determined by periodic revenue achievements over a thirty-month period. Earn-out payments have no maximum limit, but if certain targets are not met, there will be no earn-out payment for the applicable measurement period. The estimated fair value of the Tellutax Contingent Consideration recorded as of the acquisition date was $2,200, see Note 4 for information on recurring fair value adjustments after the acquisition date. Systax On January 7, 2020, the Company acquired a 60% controlling interest in Systax, a provider of Brazilian transaction tax content and software. Cash consideration for the purchase was $12,374. This acquisition provided the Company with full access to a sizeable database of Brazilian tax content that is critical to supporting its global multi-national customers’ business expansion into Brazil. The Company has a contractual purchase commitment to acquire the remaining 40% equity interest from the original Systax Quotaholders incrementally between 2021 through 2024. Future purchase commitment payments for these incremental acquisition amounts are based on a multiple of Systax revenue and earnings before interest, depreciation, amortization and income taxes (“EBITDA”) performance at the end of 2020, 2022 and 2023, whereby the Company will have full ownership after the final transaction in 2024. Management determined these future purchase commitments to be a forward contract, resulting in the Company being required to estimate and record an estimated future purchase commitment amount (the “Purchase Commitment Liability”) in connection with recording the initial purchase. The fair value of the Purchase Commitment Liability at the acquisition date was finalized to be $12,592. This amount will fluctuate as a result of changes in foreign currency exchange rates and is reflected in purchase commitment and contingent consideration liabilities in the condensed consolidated balance sheets, with such changes in exchange rates being reflected in other comprehensive income or loss in the condensed consolidated statements of comprehensive loss. The Purchase Commitment Liability was $9,750 at December 31, 2020 reflecting the impacts of such fluctuations in foreign currency exchange rates. Adjustments to the settlement date value that arise as a result of remeasurement at future balance sheet dates will be recorded as interest expense related to financing costs in the consolidated statements of comprehensive income or loss in the period the change is identified. No such adjustments have been recorded through June 30, 2021. The Company acquired an additional 5% equity interest of Systax through a Purchase Commitment Liability payment of $788 during the three and six months ended June 30, 2021, increasing the Company’s equity interest in Systax to 65% and reducing the remaining Purchase Commitment Liability to $9,334 at June 30, 2021.

FINANCIAL INSTRUMENTS AND FAIR

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS	6 Months Ended
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS	Jun. 30, 2021
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS	4. FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company has investments in money market accounts, which are included in cash and cash equivalents on the condensed consolidated balance sheets. Fair value inputs for these investments are considered Level 1 measurements within the Fair Value Hierarchy since money market account fair values are known and observable through daily published floating net asset values. The following table summarizes the Company’s Fair Value Hierarchy for its financial assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Using As of June 30, 2021 Fair Value Prices in active markets for identical assets (Level 1) Significant other observable inputs Significant unobservable inputs (Level 3) Money market funds $ 17,201 $ 17,201 $ - $ - Tellutax Contingent Consideration $ (2,276) $ - $ - $ (2,276) Fair Value Measurements Using As of December 31, 2020 Fair Value Prices in active markets for identical assets (Level 1) Significant other observable inputs Significant unobservable inputs (Level 3) Money market funds $ 265,270 $ 265,270 $ - $ - Tellutax Contingent Consideration As discussed in Note 3, the Tellutax Contingent Consideration is based on three potential earn-out payments determined by periodic revenue achievements over a thirty-month period. Such estimate represents a recurring fair value measurement with significant unobservable inputs, which management considers to be Level 3 measurements under the Fair Value Hierarchy. The significant assumptions used in these calculations included forecasted results and the estimated likelihood for each performance scenario. The estimated fair value of the Tellutax Contingent Consideration was determined using a Monte Carlo Simulation valuation as of the acquisition date of January 25, 2021. Management performed a present value analysis as of June 30, 2021 using the outputs of the Monte Carlo Simulation as of the acquisition date, the term of 4.3 years as of the acquisition date was reduced to 3.9 years as of June 30, 2021 to reflect the passage of time, resulting in a $(76) fair value adjustment increasing the carrying value of the Tellutax Contingent Consideration liability at June 30, 2021 which was recorded in other operating expense, net for the three and six months ended June 30, 2021. Management used this approach as there were no significant changes identified in forecasted results or the estimated likelihood for each performance scenario since the acquisition date which could result in significant changes to potential earn-out payments. Tellutax Contingent Consideration fair value as of June 30, 2021 and the acquisition date, and unobservable inputs used for the Monte Carlo Simulation valuation as of the acquisition date were as follows: June 30, 2021 January 25, 2021 Liability Fair Value Fair Value Valuation Technique Unobservable Inputs Tellutax Contingent Consideration $ (2,276) $ (2,200) Monte Carlo Simulation Revenue volatility 95.0 % Revenue discount rate 20.3 % Term (in years) 4.3 Changes in the fair value of Level 3 Tellutax Contingent Consideration during the six months ended June 30, 2021 were as follows: Tellutax Contingent Consideration Balance, January 1, 2021 $ — Acquisition of Tellutax (2,200) Fair value adjustments (76) Foreign currency translation adjustments — Balance, June 30, 2021 $ (2,276) Assets and Liabilities for Which Fair Value is Only Disclosed The residual carrying amount of cash and cash equivalents and the carrying amount of funds held for customers were the same as their respective fair values and are considered Level 1 measurements. The carrying amounts for accounts receivable, accounts payable, and accrued expenses approximate their relative fair values due to their short-term nature. Non-recurring Fair Value Measurements The Taxamo Acquisition on May 12, 2021 and the Tellutax Acquisition on January 25, 2021, were accounted for as business combinations and the total purchase price for each acquisiton was allocated to the net assets acquired and liabilities assumed based on their estimated fair values. See Note 3.

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	6 Months Ended
PROPERTY AND EQUIPMENT	Jun. 30, 2021
PROPERTY AND EQUIPMENT
PROPERTY AND EQUIPMENT	5. PROPERTY AND EQUIPMENT The major components of property and equipment are as follows: As of June 30, As of December 31, 2021 2020 (unaudited) Leasehold improvements $ 21,017 $ 20,907 Equipment 41,485 41,410 Computer software purchased 11,684 11,620 Internal-use software developed: Cloud-based customer solutions 67,037 65,423 Internal systems and tools 28,889 25,349 Furniture and fixtures 7,679 7,674 In-process internal-use software 12,636 3,304 190,427 175,687 Less accumulated depreciation (128,816) (119,130) Property and equipment, net $ 61,611 $ 56,557 Depreciation expense for property and equipment, excluding all internal-use software developed and finance leases, was $1,902 and $1,773 for the three months ended June 30, 2021 and 2020, respectively, and $3,808 and $3,948 for the six months ended June 30, 2021 and 2020, respectively Depreciation for property and equipment, excluding internal-use software developed for cloud-based customer solutions, is reflected in depreciation and amortization in the condensed consolidated statements of comprehensive loss. Finance lease amortization was $240 and $464 for the three and six months ended June 30, 2021, respectively, and depreciation expense for assets held under capital leases was $167 and $335 for the three and six months ended June 30, 2020, respectively. Finance lease amortization and depreciation expense for assets held under capital leases are included in depreciation and amortization expense in the condensed consolidated statements of comprehensive loss. Assets under finance leases of $1,070, net of accumulated amortization of $464, at June 30, 2021 are included in property and equipment in the condensed consolidated balance sheets. Assets under capital leases of $1,360, net of accumulated depreciation of $1,370, at December 31, 2020, are included in property and equipment in the condensed consolidated balance sheets. The major components of internal-use software are as follows: As of June 30, As of December 31, 2021 2020 (unaudited) Internal-use software developed $ 95,926 $ 90,772 Less accumulated depreciation (71,868) (65,090) 24,058 25,682 In-process internal-use software 12,636 3,304 Internal-use software developed, net $ 36,694 $ 28,986 Amounts capitalized for internal-use software and included in property and equipment additions on the condensed consolidated statements of cash flows are as follows: For the six months ended June 30, For the six months ended December 31, 2021 2020 (unaudited) (unaudited) Cloud-based customer solutions $ 8,232 $ 7,731 Internal systems and tools 6,253 939 Total $ 14,485 $ 8,670 In-process internal-use software developed is not depreciated until it is available for its intended use. Depreciation expense for internal-use software developed for cloud-based customer solutions for the three months ended June 30, 2021 and 2020, was $2,669 and $2,453, respectively, and was $5,345 and $4,464 for the six months ended June 30, 2021 and 2020, respectively, and is included in cost of revenues, software subscriptions in the condensed consolidated statements of comprehensive loss. Depreciation expense for internal-use software developed for internal systems and tools for the three months ended June 30, 2021 and 2020, was $736 and $565, respectively, and was $1,433 and $1,091 for the six months ended June 30, 2021 and 2020, respectively, and is included in depreciation and amortization in the condensed consolidated statements of comprehensive loss.

CAPITALIZED SOFTWARE

CAPITALIZED SOFTWARE	6 Months Ended
CAPITALIZED SOFTWARE	Jun. 30, 2021
CAPITALIZED SOFTWARE
CAPITALIZED SOFTWARE	6. CAPITALIZED SOFTWARE Capitalized software includes acquired software and direct labor and related expenses for software developed for sale for new products and enhancements to existing products. The major components of capitalized software are as follows: As of June 30, As of December 31, 2021 2020 (unaudited) Capitalized software $ 65,980 $ 63,071 Less accumulated amortization (38,567) (32,217) 27,413 30,854 In-process capitalized software 6,951 1,135 Capitalized software, net $ 34,364 $ 31,989 Software development costs capitalized for the three months ended June 30, 2021 and 2020 were $2,904 and $3,558, respectively, and were $8,725 and $7,264 for the six months ended June 30, 2021 and 2020, respectively. During the six months ended June 30, 2021, an acquisition date value of $3,600 for developed technology the Company acquired in the Tellutax business combination was recorded and is reflected in in-process capitalized software as the Company undertakes necessary enhancements to integrate it with the Company’s existing software architecture. Capitalized software amortization expense for the three months ended June 30, 2021 and 2020 was $3,182 and $3,022, respectively, and was $6,350 and $5,578 for the six months ended June 30, 2021 and 2020, respectively, and is included in cost of revenues, software subscriptions in the condensed consolidated statements of comprehensive loss.

LEASES

LEASES	6 Months Ended
LEASES	Jun. 30, 2021
LEASES
LEASES	7. LEASES The Company leases office space, IT equipment and office equipment. Leases with an initial term of 12 months or less are not recorded on the condensed consolidated balance sheets and lease expense is recognized over the term of these leases on a straight-line basis. The Company’s leases have remaining terms of up to 8 years. The following table sets forth the Company’s lease assets and liabilities and their balance sheet location as follows: As of June 30, Balance Sheet Location 2021 Lease assets: (unaudited) Operating lease right-of-use assets Operating lease right-of-use assets $ 22,156 Finance lease assets Property and equipment, net (Note 5) 1,070 Total lease assets $ 23,226 Lease liabilities: Current: Operating lease liabilities Current portion of operating lease liabilities $ 3,641 Finance lease liabilities Current portion of finance lease liabilities 271 Total current lease liabilities 3,912 Non-current: Operating lease liabilities Operating lease liabilities, net of current portion 26,726 Finance lease liabilities Finance lease liabilities, net of current portion 334 Total non-current lease liabilities 27,060 Total lease liabilities $ 30,972 The major components of lease cost are as follows: For the three months ended June 30, For the six months ended June 30, 2021 2021 (unaudited) (unaudited) Operating lease cost $ 1,181 $ 2,350 Finance lease cost: Amortization of lease assets 240 463 Interest on lease liabilities 3 10 Total lease cost $ 1,424 $ 2,823 The weighted-average term and discount rate for leases are as follows: As of June 30, 2021 (unaudited) Weighted-average remaining lease term (years): Operating leases 7.0 Finance leases 1.5 Weighted-average discount rate: Operating leases 2.3 % Finance leases 2.3 % Lease liability maturities for the next five years and thereafter are as follows as of June 30, 2021: Operating Leases Finance Leases (unaudited) Remainder of 2021 (six months remaining) $ 2,810 $ 269 2022 4,542 289 2023 4,460 60 2024 4,464 10 2025 4,382 — Thereafter 12,531 — Total lease payments 33,189 628 Less: Imputed interest (2,822) (23) Present value of lease liabilities $ 30,367 $ 605 Lease liability maturities for the next five years and thereafter under the previous lease accounting standard are as follows: As of December 31, 2020 Operating Leases Capital Leases 2021 $ 5,442 $ 915 2022 4,518 230 2023 4,459 — 2024 4,464 — 2025 4,382 — Thereafter 12,531 — Total Lease Payments $ 35,796 1,145 Less amount representing interest (38) Present value of minimum lease payments 1,107 Less current portion (882) Capital lease obligations, net of current portion $ 225

GOODWILL AND OTHER INTANGIBLE A

GOODWILL AND OTHER INTANGIBLE ASSETS	6 Months Ended
GOODWILL AND OTHER INTANGIBLE ASSETS	Jun. 30, 2021
GOODWILL AND OTHER INTANGIBLE ASSETS
GOODWILL AND OTHER INTANGIBLE ASSETS	8. GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill and other intangible assets are as follows: As of June 30, As of December 31, 2021 2020 (unaudited) Goodwill $ 218,184 $ 16,329 Other intangible assets, net 2,167 2,382 $ 220,818 $ 18,711 The changes in the carrying amount of goodwill for the six months ended June 30, 2021 are as follows: Balance, January 1, 2021 $ 16,329 Acquisition of Taxamo 201,580 Acquisition of Tellutax 4,700 Foreign currency translation adjustments (4,425) Balance, June 30, 2021, gross 218,184 Accumulated impairment losses — Balance, June 30, 2021, net $ 218,184 The Company has recognized various amortizable other intangible assets in connection with acquisitions, including related to customer relationships, technology, and tradenames. The following tables provide additional information for other intangible assets, which are individually not material to the condensed consolidated financial statements: As of June 30, As of December 31, 2021 2020 (unaudited) Other intangible assets Weighted average amortization period (years) 5.5 5.5 Gross value $ 2,952 $ 2,825 Accumulated amortization (785) (443) Carrying value $ 2,167 $ 2,382 For the three months ended June 30, 2021 Cost of Revenues, Software Subscriptions Selling and Amortization of acquired intangible assets $ 66 $ 86 152 For the six months ended June 30, 2021 Cost of Revenues, Software Subscriptions Selling and Amortization of acquired intangible assets $ 127 $ 170 297

DEBT

DEBT	6 Months Ended
DEBT	Jun. 30, 2021
DEBT
DEBT	9. Credit Agreement On March 31, 2020, the Company entered into a credit agreement with a bank, which was subsequently amended on April 3, 2020 to permit another bank to be a party to the agreement, consisting of a $175,000 term loan (the “Term Loan”) and a $100,000 committed line of credit (the “Line of Credit”) (collectively, the “Credit Agreement”). A portion of the Offering proceeds was used to repay the $175,000 Term Loan in full on July 31, 2020. The Line of Credit matures in March 2025 and had no outstanding borrowings at June 30, 2021 or December 31, 2020. The Company has the option to select an applicable interest rate at either the bank base rate plus an applicable margin (the “Base Rate Option”) or the LIBOR plus an applicable margin (the “LIBOR Option”). The applicable margins are determined by certain financial covenant The Credit Agreement is collateralized by certain assets of the Company and contains financial and operating covenants. The Company was in compliance with these covenants at June 30, 2021.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	6 Months Ended
STOCKHOLDERS' EQUITY	Jun. 30, 2021
STOCKHOLDERS' EQUITY
STOCKHOLDERS' EQUITY	10 . Recapitalization On July 28, 2020, the Company filed its amended and restated certificate of incorporation with the Delaware Secretary of State to: (i) effect a three-for-one forward stock split (the “Stock Split”); (ii) establish a new capital structure for the Company (the “New Capital Structure”); and (iii) effect a share exchange (the “Share Exchange”) (collectively, the “Recapitalization”). The Stock Split resulted in each one share owned by a stockholder being exchanged for three connection with the New Capital Structure. The effect of the Stock Split and Share Exchange are recognized retrospectively in the condensed consolidated financial statements. In connection with the New Capital Structure, Treasury Stock was retired and amounts associated with the Treasury Stock were reclassified to additional paid in capital. Thus, at June 30, 2021 and December 31, 2020, there was no Treasury Stock. Common Stock During the three months ended March 31, 2021 and June 30, 2021, the Company issued 640 and 462 shares of Class A, respectively, related to the exercise of stock options, net of 356 and 219 shares, respectively, returned to the Company in lieu of payment of the exercise price and taxes due on these exercises. During the three months ended March 31, 2021 the Company issued 5 shares of Class A in connection with the vesting of RSUs, net of 1 share returned to the Company in lieu of payment of taxes due on the vesting of these RSUs. During the three months ended June 30, 2021, 234 shares of Class A were issued in connection with the vesting of RSAs. No Class A shares were issued during the three months ended March 31, 2021 and June 30, 2021 in connection with the vesting of RSAs and RSUs, respectively. During the three months ended June 30, 2021, a stockholder exchanged 12,100 shares of Class B for an equivalent number of shares of Class A. At June 30, 2020, the Company had 147 shares of former Class A common stock and 120,443 shares of former Class B common stock outstanding. At June 30, 2020, members of a family (the “Family”) owned all 147 outstanding shares of former Class A common stock and 120,270 shares of the former Class B common stock. The remaining 173 shares of former Class B common stock outstanding were owned by non-Family members in connection with the exercise of stock options in April 2020 for cash of $53. There were no dividend or liquidation preference differences between the former Class A and former Class B shares. There were common stock equivalents outstanding at June 30, 2020 held by non-Family members that entitled such holders to receive an equivalent number of former Class B shares upon exercise. In connection with establishing the New Capital Structure in July 2020, the stockholders authorized 450,000 shares of common stock, par value $0.001 per share, and 30,000 shares of preferred stock, par value $0.001 per share. In connection with the New Capital Structure, common stock is divided into two classes, Class A with one vote per share, and Class B with ten votes per share. The rights of the holders of Class A and Class B are identical, except with respect to voting and conversion rights. Upon transfer of Class B shares to a non-Family member, such shares will automatically convert to an equivalent number of Class A shares with the respective voting rights attributable to such new shares. Authorized Class A and Class B shares are 300,000 and 150,000 shares, respectively. There are no dividend or liquidation preference differences between Class A and Class B. In connection with the Share Exchange in July 2020, the Family members exchanged each share of former Class A and former Class B for the equivalent number of Class B shares established as part of the New Capital Structure. In addition, the non-Family members exchanged their former Class B shares for an equivalent number of Class A shares established as part of the New Capital Structure. No funds were exchanged in connection with the Share Exchange, and the aggregate number of shares outstanding both immediately prior to and after the Share Exchange remained the same at 120,590. In addition, common stock equivalents, all of which were held by non-Family members and which were previously exercisable into former Class B shares, became exercisable into Class A shares established as part of the New Capital Structure. Historical earnings per share information for all periods presented prior to the Offering was retrospectively restated similar to the treatment of a stock split to reflect the Share Exchange as management concluded that there was no economic value attributable to such exchange of shares in connection with the Recapitalization. See Note 11. Distributions The board of directors (the “Board”) declared and paid aggregate distributions pro rata to stockholders of the former Class A and Class B common stock of $123,185 ($1.02 per share) and $4,010 ($0.03 per share) during the three months ended June 30, 2020 and March 31, 2020, respectively. Tax Sharing Agreement Payments In connection with termination of the Company’s S-Corporation status effective July 27, 2020, the Company entered into a Tax Sharing Agreement with the former S-Corporation shareholders. See Note 1. The Tax Sharing Agreement, as amended on June 30, 2021, requires the Company to finalize the S-Corporation income tax returns for the short period ended July 26, 2020 no later than August 15, 2021 (previously June 30, 2021 prior to the amendment). The Company is required to settle any remaining liability for taxes to the former S-Corporation shareholders within 15 days thereafter under the amended Tax Sharing Agreement. All obligations of the Company under the Tax Sharing Agreement are satisfied by adjustments of additional paid in capital. During the three months ended June 30, 2021, the Company distributed $2,700 to the former S-Corporation shareholders under the Tax Sharing Agreement in connection with preliminary estimates of obligations for income taxes related to the allocation of taxable income to the S-Corporation short tax period ended July 26, 2020.

EARNINGS PER SHARE

EARNINGS PER SHARE	6 Months Ended
EARNINGS PER SHARE	Jun. 30, 2021
EARNINGS PER SHARE
EARNINGS PER SHARE	11. EARNINGS PER SHARE The table below illustrates the calculation of basic and diluted net income (loss) per common share for the Class A common and Class B common for the periods reflected below. The weighted average shares outstanding have been retrospectively restated to reflect the Share Exchange for all periods prior to the Offering, resulting in the Class A shares representing non-Family-owned shares and Class B representing Family-owned shares for all periods presented. See Note 10 for further information on the Share Exchange. For the three months ended For the six months ended June 30, June 30, Class A common stock: 2021 2020 2021 2020 (unaudited) (unaudited) Numerator, basic: Net income (loss) attributable to all stockholders $ 808 $ (29,075) $ 3,096 $ (58,139) Class A common stock as a percentage of total shares outstanding, basic 1 23.54 % 0.11 % 13.08 % 0.03 % Net income (loss) attributable to Class A stockholders, basic 1 $ 190 $ (32) $ 644 $ (16) Numerator, diluted: Net income (loss) attributable to all stockholders $ 808 $ (29,075) $ 3,096 $ (58,139) Class A common stock as a percentage of total shares outstanding, diluted 1 28.37 % 0.11 % 26.20 % 0.03 % Net income (loss) attributable to Class A stockholders, diluted 1 $ 229 $ (32) $ 811 $ (16) Denominator, basic and diluted: Weighted average Class A common stock, basic 1 34,726 132 30,592 66 Dilutive effect of common stock equivalents 2 9,985 — 10,765 — Weighted average Class A common stock, diluted 1 44,711 132 41,357 66 Net income (loss) per Class A share, basic 1 $ 0.01 $ (0.24) $ 0.02 $ (0.24) Net income (loss) per Class A share, diluted 1 $ 0.01 $ (0.24) $ 0.02 $ (0.24) 1 2 For the three months ended For the six months ended June 30, June 30, Class B common stock: 2021 2020 2021 2020 (unaudited) (unaudited) Numerator, basic: Net income (loss) attributable to all stockholders $ 808 $ (29,075) $ 3,096 $ (58,139) Class B common stock as a percentage of total shares outstanding, basic 1 76.46 % 99.89 % 79.20 % 99.97 % Net income (loss) attributable to Class B stockholders, basic 1 $ 618 $ (29,043) $ 2,452 $ (58,123) Numerator, diluted: Net income (loss) attributable to all stockholders $ 808 $ (29,075) $ 3,096 $ (58,139) Class B common stock as a percentage of total shares outstanding, diluted 1 71.63 % 99.89 % 73.80 % 99.97 % Net income (loss) attributable to Class B stockholders, diluted 1 $ 579 $ (29,043) $ 2,285 $ (58,123) Denominator, basic and diluted: Weighted average Class B common stock, basic 1 112,804 120,417 116,460 120,417 Dilutive effect of common stock equivalents 1 — — — — Weighted average Class B common stock, diluted 1 112,804 120,417 116,460 120,417 Net income (loss) per Class B share, basic 1 $ 0.01 $ (0.24) $ 0.02 $ (0.48) Net income (loss) per Class B share, diluted 1 $ 0.01 $ (0.24) $ 0.02 $ (0.48) 1 The net income (loss) attributable to Class B stockholders, basic and diluted, and the weighted average Class B common stock basic and diluted, as of and for the three and six months ended June 30, 2020 were retrospectively restated to effect the Share Exchange. As there were no changes to the total number of shares outstanding as a result of the Share Exchange, there was no change to net loss per Class B share, basic or diluted from previously disclosed results for the three and six months ended June 30, 2020.

STOCK-BASED AWARD PLANS

STOCK-BASED AWARD PLANS	6 Months Ended
STOCK-BASED AWARD PLANS	Jun. 30, 2021
STOCK-BASED AWARD PLANS
STOCK-BASED AWARD PLANS	12. STOCK-BASED AWARD PLANS On the effective date of the Offering, the Company adopted the 2020 Plan and the ESPP. The 2020 Plan provides the ability to grant cash and equity-based incentive awards to eligible employees, directors and service providers in order to attract, retain and motivate those that make important contributions to the Company. The 2020 Plan provides for the award of stock options, RSAs, RSUs, SARs and other cash compensation. The ESPP provides eligible employees with rights during each six-month ESPP offering period to purchase shares of the Company’s Class A common at the ESPP Discount through payroll deductions, except for the initial offering period (July 28 to November 30, 2020) whereby the participants were permitted to make lump sum contributions to the ESPP for such period. Amounts withheld or received from participants are reflected in accrued salaries and benefits in the condensed consolidated balance sheets until such shares are purchased. Amounts withheld from participants for the offering period ending November 30, 2021 aggregated $152 as of June 30, 2021. Prior to the adoption of the 2020 Plan, the Company had a SAR plan for the purpose of providing incentives to key members of management and consultants to contribute to the growth and financial success of the Company. As a result of the Offering, SAR participants were offered the option to either redeem their SARs upon the occurrence of the Offering or amend their SARs pursuant to which, upon effectiveness of the 2020 Plan, such SARs would become options to purchase shares of Class A common stock under the 2020 Plan (the “SAR Exchange Offer”). All SAR participants eligible to receive the SAR Exchange Offer accepted and had their outstanding SARs converted to stock options with equivalent terms under the 2020 Plan at the Offering effective date (the “Converted SARs”) of July 28, 2020. This was considered a modification of these SAR awards which was recorded in the respective quarter this occurred. The SAR plan was subsequently retired (“Retired SAR Plan”) and any SARs issued after such date will be granted under the 2020 Plan. Prior to the adoption of the 2020 Plan, the Company had options outstanding to purchase shares of former Class B common stock. U pon the effectiveness of the Offering these options were amended and exchanged for options to purchase an equivalent number of Class A shares at the same exercise price and vesting, subject to many of the terms of the 2020 Plan. These options remain subject to expiration in connection with a Triggering Event under the terms of the original option agreements (the “Amended Options”). Any options issued subsequent to this exchange will be granted under the 2020 Plan. 2020 Plan As of June 30, 2021, 854 shares of Class A common were available for issuance under the 2020 Plan. Awards issued under the 2020 Plan vest based on service criteria established by the Board. The Company has elected to account for forfeitures as they occur rather than estimate forfeitures at date of grant. Retired SAR Plan At June 30, 2020, the fair value of the common stock underlying the SAR Awards was determined by the Board with assistance from management and an independent third-party valuation firm. The determination of value used the market and income approaches, with an adjustment for marketability discount pertinent to private company entities in arriving at the per share fair value (the “valuation methodology”). Under the market approach, the guideline public company method is used, which estimates the fair value of the Company based on market prices of stock of guideline public companies. The income approach involves projecting the future benefits of owning an asset and estimating the present value of those future benefits by discounting them based upon the time value of money and the investment risks associated with ownership. At the end of 2019, due to the consideration by the Board of pursuing the Offering, the valuation methodology began to consider the impact of such an event on the value of the Company’s common stock underlying the awards. As the Company approached the Offering effective date, this resulted in increases in the value of the SAR Awards which resulted in corresponding increases to compensation expense during 2020 which exceeded historical results. Amended Options Prior to the amendment of the options in connection with the Offering in July 2020, the options permitted holders to put their exercised shares back to the Company, thus the options were classified as temporary equity and included in “Options for Redeemable Shares” on the condensed consolidated statements of changes in equity (deficit) at June 30, 2020 and March 31, 2020. The Company recorded an increase in the value of Options for Redeemable Shares of $14,637 and $29,879 during the three and six months ended June 30, 2020, respectively, pertaining to the 3,676 options outstanding at June 30, 2020. As all options outstanding were fully vested, no related compensation expense was recorded for the six months ended June 30, 2020. In connection with the amendment, the option holders’ ability to put the exercised Amended Option shares to the Company in order to attain liquidity was exchanged for the right by the holders to exercise these options and sell the related shares on the NASDAQ exchange. As a result of the put right no longer being applicable, the options were no longer considered temporary equity and were reclassified to stockholders’ equity at the time of the exchange. Options under 2020 Plan The following table summarizes activity for options outstanding under the 2020 Plan: Weighted Weighted Average Average Remaining Aggregate Exercise Contractual Intrinsic 2020 Plan Option Activity Units Price Life (Years) Value Outstanding at January 1, 2021 11,876 $ 2.44 Granted 263 $ 31.51 Forfeited (281) $ 3.50 Exercised (1,677) $ 2.14 $ 35,882 2020 Plan options outstanding at June 30, 2021 10,181 $ 3.21 5.11 $ 190,675 2020 Plan options exercisable at June 30, 2021 5,895 $ 1.77 3.36 $ 118,920 The detail of options outstanding, vested and exercisable under the 2020 Plan as of June 30, 2021 is as follows: Options Outstanding Options Vested and Exercisable Weighted Weighted Average Average Exercise Prices Units Life (Years) Units Life (Years) $0.15 to $0.71 2,234 * 2,234 — $2.15 548 3.61 548 3.61 $2.50 2,431 4.99 1,801 4.86 $2.67 650 5.68 273 5.69 $3.17 1,415 6.78 665 6.76 $3.73 1,957 8.31 371 8.01 $4.70 683 8.61 — — $17.66 12 9.87 — — $32.16 251 9.67 3 9.67 10,181 5,895 *Amended Options have indefinite contractual lives The Board intends all options granted to be exercisable at a price per share not less than the per share fair market value of the Company’s Class A common stock underlying the options on the date of grant. Compensation expense for new option awards issued subsequent to the Offering to participants under the 2020 Plan are measured based on the grant date fair value of the awards and recognized in the condensed consolidated statements of comprehensive loss over the period during which the participant is required to perform the requisite services. The vesting period is generally one There were no options issued or outstanding under the 2020 Plan for the three months ended June 30, 2020. The Company issued 251 options and 12 options under the 2020 Plan during the three months ended March 31 and June 30, 2021, respectively. The assumptions used in the Black-Scholes model to determine the value of the options issued during these periods are as follows: Option Valuation Period Q1 2021 Q2 2021 Fair market value of common stock $ 32.16 $ 17.66 Volatility 36.8 % 36.8 % Expected term (years) 6.0 6.0 Expected dividend yield — % — % Risk-free interest rate 0.4 % 0.4 % The fair market value of common stock reflects the market closing price on NASDAQ on the respective option grant date. As of the valuation dates, the Company lacked sufficient historical data on the volatility of its stock price. Selected volatility is representative of expected future volatility and was based on the historical and implied volatility of comparable publicly traded companies over a similar expected term. The expected term represents the term the options are expected to be exercised over, which differs from the term of the option grants which is ten years. The Company does not expect to pay dividends. The risk-free interest rate was based on the rate for a U.S. Treasury zero-coupon issue with a term that closely approximates the expected term of the option grants. Restricted Stock Units The following table summarizes RSU activity for the six months ended June 30, 2021: Weighted Average Grant Date Fair Units Value Per Share Outstanding at January 1, 2021 101 $ 23.80 Granted 352 30.73 Vested (7) 34.78 Forfeited (15) 28.86 Outstanding at June 30, 2021 431 $ 29.50 There were no RSUs issued or outstanding for the six months ended June 30, 2020. Stock-based compensation cost for RSUs is measured based on the fair value of the Company’s underlying common stock on the date of grant and is recognized on a straight-line basis in the condensed consolidated statements of comprehensive loss over the period during which the participant is required to perform services in exchange for the award, which is generally one In connection with the Taxamo acquisition, certain continuing employees of Taxamo received RSUs with service and performance conditions covering up to 1,230 shares of our Class A common stock (“PSUs”) with an aggregate grant date fair value of $21,729 that will be accounted for as post-acquisition compensation expense over the vesting period. The performance-based condition will be satisfied upon meeting certain performance targets for the year ended 2023. As of June 30, 2021, it is not probable that these targets will be met, thus no compensation expense has been recorded to date related to these PSUs. Restricted Stock Awards The following table summarizes RSA activity for the six months ended June 30, 2021: Weighted Average Grant Date Fair Units Value Per Share Outstanding at January 1, 2021 670 $ 19.00 Granted 59 17.66 Vested (234) 19.00 Forfeited (18) 19.00 Outstanding at June 30, 2021 477 $ 18.90 There were no RSAs issued or outstanding for the six months ended June 30, 2020. Stock-based compensation cost for RSAs is measured based on the fair value of the Company’s underlying common stock on the date of grant and is recognized on a straight-line basis in the condensed consolidated statements of comprehensive loss over the period during which the participants are required to perform services in exchange for the award, which is generally one Employee Stock Purchase Plan The ESPP permits participants to purchase Class A common stock through payroll deductions of up to a specified percentage of their eligible compensation. The maximum number of shares that may be purchased by a participant during any offering period is determined by the plan administrator in advance of each offering period. On the first trading day of each offering period, each participant will automatically be granted an option to purchase shares of Class A common. The option will expire at the end of the applicable offering period and will be exercised at that time to the extent of the payroll deductions accumulated or contributions made during such offering period. The purchase price of the shares, in the absence of a contrary designation, is 15% of the lower of the fair value of the Class A common on the first or last day of the ESPP offering period. Participants may voluntarily end their participation in the plan at any time during a specified period prior to the end of the applicable offering period and will be paid their accrued payroll deductions and related contributions, if applicable, that have not yet been used to purchase shares of Class A common. If a participant withdraws from the plan during an offering period, the participant cannot rejoin until the next offering period. Participation ends automatically upon a participant’s termination of employment. A total of 1,000 shares of Class A common were initially reserved for issuance under the ESPP. The number of shares available for issuance under the ESPP will be increased annually on January 1 of each calendar year beginning in 2021 and ending in and including 2030, by an amount equal to the lesser of (i) 1% of the shares of Class A and Class B common stock outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares as is determined by the Board, provided that no more than 16,000 shares of Class A common stock may be issued. The ESPP is administered by a committee of the Board. The Company recorded stock-based compensation expense of $133 and $263 for the three and six months ended June 30, 2021, respectively, related to the ESPP. Class A common stock purchased under the ESPP for the six-month offering period ended May 31, 2021 aggregated 60 shares. As of June 30, 2021, there was approximately The fair value of ESPP purchase rights is comprised of the value of the 15% ESPP Discount and the value associated with the Call/Put over the respective ESPP offering period. The value of the Call/Put for the previous offering period (December 1, 2020 – May 31, 2021) and the current offering period (June 1, 2021 – November 30, 2021) was estimated using the Black-Scholes model with the following assumptions: Previous Current Offering Period Offering Period Fair market value of common stock $ 25.83 $ 19.89 Volatility 35.10 % 35.10 % Expected term (years) 0.50 0.50 Expected dividend yield — % — % Risk-free interest rate 0.12 % 0.12 % The Company lacks sufficient historical data on the volatility of its stock price. Selected volatility is representative of expected future volatility and was based on the historical and implied volatility of comparable publicly traded companies over a similar expected term. The expected term represents the term of the ESPP offering period, which is generally six months. The Company does not expect to pay dividends. The risk-free interest rate was based on the rate for a U.S. Treasury zero-coupon issue with a term that closely approximates the expected term of the award at the date nearest the offering term. Stock-Based Compensation The Company recognized total stock-based compensation cost related to incentive awards as follows: For the three months ended For the six months ended June 30, June 30, 2021 2020 2021 2020 Stock-based compensation expense: SARs and Converted SARs $ 3,520 $ 41,676 $ 6,911 $ 76,596 Stock options 393 — 770 — RSUs 793 — 1,229 — RSAs 1,446 — 3,655 — ESPP 133 — 263 — Total stock-based compensation expense $ 6,285 $ 41,676 $ 12,828 $ 76,596 The Company recognized stock-based compensation cost in the condensed consolidated statements of comprehensive loss as follows: For the three months ended For the six months ended June 30, June 30, 2021 2020 2021 2020 Stock-based compensation expense: Cost of revenues, software subscriptions $ 572 $ 4,168 $ 1,132 $ 7,660 Cost of revenues, services 622 6,251 1,216 11,489 Research and development 571 4,168 1,132 7,660 Selling and marketing 1,433 8,335 2,720 15,319 General and administrative 3,087 18,754 6,628 34,468 Total stock-based compensation expense $ 6,285 $ 41,676 $ 12,828 $ 76,596

LEGAL PROCEEDINGS

LEGAL PROCEEDINGS	6 Months Ended
LEGAL PROCEEDINGS	Jun. 30, 2021
LEGAL PROCEEDINGS
LEGAL PROCEEDINGS	13. LEGAL PROCEEDINGS The Company may become involved in various lawsuits and legal proceedings, which arise, in the ordinary course of business. However, litigation is subject to inherent uncertainties, and an adverse result in these or other matters may arise from time to time that may harm the Company’s business. The Company is not aware of any such legal proceedings or claims that management believes will have a material adverse effect on its business, financial condition, or operating results.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Jun. 30, 2021
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Nature of Business	Nature of Business Vertex, Inc. (“Vertex”) and its direct and indirect wholly owned subsidiaries (collectively, the “Company”) operate as solutions providers of state, local and value added tax calculation, compliance and analytics, offering software products which are sold through software license and software as a service (“cloud”) subscriptions. The Company also provides implementation and training services in connection with its software license and cloud subscriptions, transaction tax returns outsourcing, and other tax-related services. The Company sells to customers located throughout the United States of America (“U.S.”) and internationally.
Basis of Consolidation	Basis of Consolidation The condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”) and include the accounts of the Company. All intercompany transactions have been eliminated in consolidation. On May 12, 2021, the Company acquired 95% of the outstanding equity of EVAT Solutions Limited (“EVAT”) and its subsidiaries, doing business as Taxamo (collectively “Taxamo”), a cloud-based provider of tax and payment automation for global eCommerce and marketplaces. As the Company has a controlling interest in Taxamo, its accounts have been included in the condensed consolidated financial statements from the acquisition date. On January 7, 2020, the Company acquired a 60% controlling interest in Systax Sistemas Fiscais LTDA (“Systax”), a provider of Brazilian transaction tax content and software. Systax is considered a Variable Interest Entity (“VIE”) and its accounts have been included in the condensed consolidated financial statements from the acquisition date. Systax was determined to be a VIE as Vertex is the primary beneficiary of the equity interests in Systax and participates significantly in the variability in the fair value of Systax’s net assets.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial information and include the accounts of the Company. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes for the year ended December 31, 2020, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 (the “2020 Annual Report”) filed with the SEC on March 15, 2021. The interim condensed consolidated balance sheet as of December 31, 2020 has been derived from audited financial statements included in the 2020 Annual Report. The accompanying interim condensed consolidated balance sheet as of June 30, 2021, the interim condensed consolidated statements of comprehensive loss and changes in equity (deficit) for the three and six months ended June 30, 2021 and 2020, and interim condensed consolidated statements of cash flows for the six months ended June 30, 2021 and 2020 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with that used to prepare the annual audited consolidated financial statements and include, in the opinion of management, all adjustments, consisting of normal and recurring items, necessary for the fair presentation of the condensed consolidated financial statements. The operating results for the three and six months ended June 30, 2021 are not necessarily indicative of the results expected for the full year ending December 31, 2021.
Segments	Segments The Company operates its business as one operating segment. For the three and six months ended June 30, 2021 approximately 7% and 6%, respectively, of the Company’s revenues were generated outside the U.S. For the three and six months ended June 30, 2020, revenues generated outside of the U.S. were approximately 3% in each respective period.
Fair Value Measurement	Fair Value Measurement Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at a measurement date. A three-level fair value hierarchy (the “Fair Value Hierarchy”) prioritizes the inputs used to measure fair value. The Fair Value Hierarchy requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs. Classification in the Fair Value Hierarchy is based on the lowest of the following levels that is significant to the measurement: Level 1 Level 2 Level 3 The Company’s assessment of the significance of an input to a fair value measurement requires judgment, which may affect the determination of fair value and the measurement’s classification within the Fair Value Hierarchy.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses during the reporting period. Significant estimates used in preparing these condensed consolidated financial statements include: (i) the estimated allowance for subscription cancellations, (ii) expected credit losses associated with the allowance for doubtful accounts; (iii) the reserve for self-insurance, (iv) assumptions related to achievement of technological feasibility for software developed for sale, (v) product life cycles, (vi) estimated useful lives and potential impairment of long-lived assets, intangible assets, (vii) potential impairment of goodwill, (viii) determination of the fair value of tangible and intangible assets acquired, liabilities assumed and consideration transferred in acquisitions, (ix) amortization period of material rights and deferred commissions (x) valuation of the Company’s stock used to measure stock-based compensation awards, (xi) Black-Scholes-Merton option pricing model (“Black-Scholes model”) input assumptions used to determine the fair value of stock-based compensation awards, (xii) measurement of future purchase commitment and contingent consideration liabilities and (xiii) the potential outcome of future tax consequences of events that have been recognized in the condensed consolidated financial statements or tax returns. Actual results may differ from these estimates.
Internal-Use Software	Internal-Use Software The Company follows Accounting Standard Codification (“ASC”) 350-40, Goodwill and Other, Internal-Use Software, 3
Software Developed for Sale	Software Developed for Sale The costs incurred for the development of computer software to be sold, leased, or otherwise marketed are capitalized in accordance with ASC 985-20, Costs of Software to be Sold, Leased or Marketed 3
Business Combinations	Business Combinations Upon acquisition of a company, the Company determines if the transaction is a business combination, which is accounted for using the acquisition method of accounting. Under the acquisition method, once control is obtained of a business, the assets acquired, liabilities assumed, consideration transferred and amounts attributed to noncontrolling interests, are recorded at fair value. The Company uses its best estimates and assumptions to assign fair value to the tangible and intangible assets acquired, liabilities assumed, consideration transferred, and amounts attributed to noncontrolling interests at the acquisition date. One of the most significant estimates relates to the determination of the fair value of these amounts. The determination of the fair values is based on estimates and judgments made by management. The Company’s estimates of fair value are based upon assumptions it believes to be reasonable, but which are inherently uncertain and unpredictable. Measurement period adjustments to these values as of the acquisition date are reflected at the time identified, up through the conclusion of the measurement period, which is the time at which all information for determination of the values of assets acquired, liabilities assumed, consideration transferred and noncontrolling interests is received, and is not to exceed one year from the acquisition date (the “Measurement Period”). Thus the Company may record adjustments to the fair value of these tangible and intangible assets acquired, liabilities assumed, consideration transferred and noncontrolling interests, with the corresponding offset to goodwill during this Measurement Period. Additionally, uncertain tax positions and tax-related valuation allowances are initially recorded in connection with a business combination as of the acquisition date. The Company continues to collect information and reevaluate these estimates and assumptions periodically and record any adjustments to preliminary estimates to goodwill, provided the Company is within the Measurement Period, with any adjustments to amortization of new or previously recorded identifiable intangibles being recorded to the consolidated statements of comprehensive loss in the period in which they arise. In addition, if outside of the Measurement Period, any subsequent adjustments to the acquisition date fair values are reflected in the consolidated statements of comprehensive loss in the period in which they arise.
Goodwill	Goodwill Goodwill represents the excess of the purchase price over the fair value of net tangible and intangible assets acquired in a business combination. The Company evaluates goodwill for impairment annually at October 1 and whenever events or circumstances make it more likely than not that impairment may have occurred.
Stock-Based Compensation	Stock-Based Compensation The Company’s Registration Statement on Form S-1 with the SEC was declared effective on July 28, 2020, resulting in the Class A shares being registered and available for trading on the NASDAQ exchange (the “Offering”). On the effective date of the Offering, the Company adopted the 2020 Incentive Award Plan (the “2020 Plan”) and the 2020 Employee Stock Purchase Plan (the “ESPP”), which provide for the award of stock appreciation rights (“SARs”), stock options (“options”), restricted stock awards (“RSAs”), restricted stock units (“RSUs”), and participation in the ESPP (collectively, the "awards"). The awards are subject to, and the Company applies, the guidance set forth in ASC 718, Compensation—Stock Compensation, ("ASC 718") for the award of equity-based instruments. The provisions of ASC 718 require a company to measure the fair value of stock-based compensation as of the grant date of the award. Stock-based compensation expense reflects the cost of employee services received in exchange for the awards. SARs are accounted for as liabilities under ASC 718 and, as such, the Company recognizes stock-based compensation expense by remeasuring the value of the SARs at the end of each reporting period and accruing the portion of the requisite service rendered at that date. Prior to July 2, 2020, the date management determined the Company was considered to have become a public entity, the Company measured SARs at their intrinsic value. After such date, management remeasured outstanding SARs using the fair value-based method under ASC 718. Stock-based compensation expense for stock options issued under the 2020 Plan after the Offering is measured based on the grant date fair value of the award and is estimated using the Black-Scholes model. Compensation cost is recognized on a straight-line basis over the requisite service or performance period associated with the award. Stock-based compensation expense for RSAs and RSUs is based on the fair value of the Company’s underlying common stock on the date of grant. Compensation cost is recognized on a straight-line basis over the requisite service or performance period associated with the award. Stock-based compensation expense for awards subject to performance-based measurement criteria is recognized when achievement of performance targets is deemed probable. The ESPP permits participants to purchase Class A common stock through payroll deductions, up to a specified percentage of their eligible compensation or a lump sum contribution amount for the initial offering period. The plan is a compensatory plan as it allows participants to purchase stock at a 15% discount from the lower of the fair value of the Class A common on the first or last day of the ESPP offering period (the “ESPP Discount”).The ESPP is accounted for as an equity classified award. Stock-based compensation expense for the ESPP is measured based on the fair value of the ESPP award at the start of the offering period. The fair value is comprised of the value of the ESPP Discount and the value associated with the variability in the Class A common stock price during the offering period (the “Call/Put”), which is estimated using the Black-Scholes model. Compensation cost is recognized on a straight-line basis over the respective offering period. The Company has elected to recognize award forfeitures as they occur.
Revenue Recognition	Revenue Recognition Revenue from contracts with customers The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers Nature of goods and services Licenses for on-premise software subscriptions provide the customer with a right to use the software as it exists when made available to the customer. Customers purchase a subscription to these licenses, which includes the related software and tax content updates (collectively “updates”) and product support. The updates and support, which are part of the subscription agreement, are essential to the continued utility of the software; therefore, the Company has determined the software and the related updates and support to be a single performance obligation. Accordingly, when on-premise software is licensed, the revenue associated with this combined performance obligation is recognized ratably over the license term as these subscriptions are provided for the duration of the license term. Revenue recognition begins on the later of the beginning of the subscription period or the date the software is made available to the customer to download. The Company’s on-premise software subscription prices in the initial subscription year are higher than standard renewal prices. The excess initial year price over the renewal price (“new sale premium”) is a material right that provides customers with the right to this reduced renewal price. The Company recognizes revenue associated with this material right over the estimated period of benefit to the customer, which is generally three years. Cloud-based subscriptions allow customers to use Company-hosted software over the contract period without taking possession of the software. The cloud-based offerings also include related updates and support. Cloud-based contracts consistently provide a benefit to the customer during the subscription period; thus, the associated revenue is recognized ratably over the related subscription period. Revenue recognition begins on the later of the beginning of the subscription period or the date the customer is provided access to the cloud-based solutions. Revenue from deliverable-based services is recognized as services are delivered. Revenue from fixed fee services is recognized as services are performed using the percentage of completion input method. The Company has elected the "right to invoice" practical expedient for revenue related to services that are billed on an hourly basis, which enables revenue to be recognized as the services are performed. The Company has determined that the methods applied to measuring its progress toward complete satisfaction of performance obligations recognized over time are a faithful depiction of the transfer of control of software subscriptions and services to customers. Significant Judgments Contracts with customers often include promises to transfer multiple products and services to a customer. Determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together may require significant judgment. Identification of the amortization periods of material rights and contract costs requires significant judgement by management. Payment terms Payment terms and conditions vary by contract, although the Company’s terms generally include a requirement of payment within 30-days. In instances where the timing of revenue recognition differs from the timing of payment, the Company has determined that its contracts do not include a significant financing component. The primary purpose of invoicing terms is to provide customers with simplified and predictable ways of purchasing products and services, not to receive financing from customers or to provide customers with financing. Cost of Revenues Cost of revenues, software subscriptions includes the direct cost to develop, host and distribute software products, the direct cost to provide customer support, and amortization of costs capitalized for software developed for sale and for internal-use software utilized for cloud-based subscriptions. Cost of revenues, services includes the direct costs of implementation, training, transaction tax returns outsourcing and other tax-related services. Reimbursable Costs Reimbursable costs passed through and invoiced to customers of the Company are recorded as services revenues with the associated expenses recorded as cost of revenues, services in the condensed consolidated statements of comprehensive loss.
Income Taxes	Income Taxes On July 27, 2020, the Company’s S-Corporation election (the “S Election”) was terminated by the Company’s stockholders in connection with the Offering. As a result, Vertex became taxable at the corporate level as a C-Corporation for U.S federal and state income tax purposes. In connection with the S Election termination, the Company entered into an agreement with the S-Corporation stockholders pursuant to which the Company has indemnified them for unpaid income tax liabilities and may be required to make future payments in material amounts to them attributable to incremental income taxes resulting from an adjustment to S-Corporation related taxable income (the “Tax Sharing Agreement”). In addition, the Tax Sharing Agreement indemnifies the S-Corporation stockholders for any interest, penalties, losses, costs or expenses arising out of any claim under the agreement. Correspondingly, the S-Corporation stockholders have indemnified the Company with respect to unpaid tax liabilities (including interest and penalties) attributable to a decrease in S-Corporation stockholders’ taxable income and a corresponding increase in our taxable income as a C-Corporation for any period. Prior to July 27, 2020, as Vertex was taxed as an S-Corporation for U.S. federal and certain states income tax purposes, net income or loss was allocated to and included on the income tax returns of the S-Corporation stockholders. Historically, the Company distributed amounts to the S-Corporation stockholders to satisfy their tax liabilities resulting from allocated net income or loss. Vertex was taxed at the corporate level in those states where the S-Corporation status was not recognized or where the state imposed a tax on an S-Corporation. Accordingly, the income tax provision or benefit was based on taxable income allocated to these states. In certain foreign jurisdictions, Vertex subsidiaries were taxed at the corporate level, and the income tax provision or benefit was based on taxable income sourced to these foreign jurisdictions.
Supplemental Cash Flow Disclosures	Supplemental Cash Flow Disclosures Supplemental cash flow disclosures are as follows for the respective periods: For the six months ended June 30, 2021 2020 (unaudited) Cash paid for interest $ 119 $ 1,360 Cash paid for income taxes, net of refunds $ 966 $ 490 Operating cash flows from operating leases $ 2,701 $ — Non-cash investing and financing activities: Purchase commitment and contingent consideration liabilities $ 12,736 $ 14,344 Remeasurement of options for redeemable shares $ — $ 29,879 Leased assets obtained in exchange for new finance lease liabilities $ 173 $ —
Recently Issued and Recently Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements As an "emerging growth company," the Jumpstart Our Business Startups Act (the “JOBS Act”) allows the Company to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. The Company has elected to delay adoption of certain new or revised accounting standards. As a result, the Company’s financial statements may not be comparable to the financial statements of issuers who are required to comply with the effective date for new or revised accounting standards that are applicable to public companies. Recently Adopted Accounting Pronouncements Leases In February 2016, the FASB issued ASU No. 2016-02, Leases The Company adopted ASU No. 2016-02 on January 1, 2021 using the modified retrospective transition method, which did not require the Company to adjust comparative periods. The Company’s lease assets and lease liabilities are recognized on the lease commencement date in an amount that represents the present value of future lease payments. The Company’s incremental borrowing rate, which is based on information available at the adoption date for existing leases and the commencement date for leases commencing after the adoption date, is used to determine the present value of lease payments. The Company elected the "package of three" practical expedients permitted under the transition guidance, which allows (i) a carry forward of the historical lease classification conclusions, (ii) management to assess whether a contract is or contains a lease, and (iii) the retention of initial direct costs for any leases that exist prior to adoption of the new standard. As a result of the adoption of ASC 842 on January 1, 2021, the Company recorded both operating lease right-of-use assets of $24,004 and operating lease liabilities of $32,562. An adjustment to retained earnings of $508, net of the deferred tax impact, was also recorded. The adoption of ASC 842 had an immaterial impact on the condensed consolidated statement of comprehensive loss for the three and six months ended June 30, 2021, and the condensed consolidated cash flow statement for the six months ended June 30, 2021. The adoption of this standard also resulted in a change in the naming convention for leases classified historically as capital leases. These leases are now referred to as finance leases within property and equipment, with corresponding short-term and long-term debt liabilities being presented as “Current portion of finance lease liabilities” and “Finance lease liabilities, net of current portion,” respectively. See Note 7 for further information. The Company does not recognize leases with an initial term less than one year (“short-term leases”) on its condensed consolidated balance sheets, and recognizes such lease payments in the condensed consolidated statements of comprehensive loss on a straight-line basis over the lease term. Leases with an option to extend the related lease term or terminate early are reflected in the lease term when it is reasonably certain that the Company will exercise such options. Credit Losses In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments Income Taxes In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes,
Risks and Uncertainties	Risks and Uncertainties In March 2020, the World Health Organization declared the outbreak of coronavirus disease 2019 (“COVID-19”) to be a pandemic. The COVID-19 pandemic is continuing to have widespread, rapidly evolving and unpredictable impacts on global society, economies, financial markets and business practices. To protect the health and well-being of Company employees and customers, substantial modifications were made to employee travel policies, and our offices were closed, and remained closed through June 30, 2021, with employees directed to work from home. In addition, conferences and other marketing events were cancelled or shifted to virtual-only, and the Company continued to participate virtually through June 30, 2021. The COVID-19 pandemic has impacted, and may continue to impact, Company operations, including employees, customers and partners, and there is substantial uncertainty regarding the nature and degree of its continued effects over time. The Company did not experience any significant reductions in sales, revenues or collections through June 30, 2021 as a result of COVID-19. The uncertainty caused by the COVID-19 pandemic could, however, impact Company billings to new customers for the remainder of 2021, and may also negatively impact Company efforts to expand revenues from existing customers as they continue to evaluate certain long-term projects and budget constraints. In addition to the potential impact on sales, the Company may see delays in collections during 2021 as customers adjust their operating protocols to accommodate implementation of new criteria to protect the health and well-being of their employees and customers. However, these delays are not expected to materially impact the business, and thus the Company has not recorded additional credit losses associated with the allowance for doubtful accounts in connection with any delays. The Company believes it has ample liquidity and capital resources to continue to meet its operating needs and to service debt and other financial obligations. The extent to which the COVID-19 pandemic impacts the business going forward will depend on numerous evolving factors that cannot reliably be predicted, including the duration and scope of the pandemic; governmental, business, and individuals’ actions in response to the pandemic; and the impact on economic activity, including the possibility of recession or financial market instability. These factors may adversely impact consumer, business and government spending on technology as well as customers’ ability to pay for Company products and services on an ongoing basis. This uncertainty also affects management’s accounting estimates and assumptions, which could result in greater variability in a variety of areas that depend on these estimates and assumptions, including estimated allowance for subscription cancellations, product life cycles and estimated lives of long-lived assets. Reclassifications Certain amounts in the prior period financial statements have been reclassified to conform to the presentation of the current period financial statements. These reclassifications had no effect on previously reported comprehensive income or loss.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	6 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	Jun. 30, 2021
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Schedule of supplemental cash flow disclosures	For the six months ended June 30, 2021 2020 (unaudited) Cash paid for interest $ 119 $ 1,360 Cash paid for income taxes, net of refunds $ 966 $ 490 Operating cash flows from operating leases $ 2,701 $ — Non-cash investing and financing activities: Purchase commitment and contingent consideration liabilities $ 12,736 $ 14,344 Remeasurement of options for redeemable shares $ — $ 29,879 Leased assets obtained in exchange for new finance lease liabilities $ 173 $ —

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	6 Months Ended
REVENUE RECOGNITION (Tables)	Jun. 30, 2021
REVENUE RECOGNITION
Schedule of disaggregation of revenue	Three months ended Six months ended June 30, June 30, 2021 2020 2021 2020 (unaudited) (unaudited) Software subscriptions: Software licenses $ 57,525 $ 57,194 $ 113,875 $ 113,919 Cloud subscriptions 32,079 20,112 59,009 39,147 Software subscriptions 89,604 77,306 172,884 153,066 Services 15,334 13,965 30,290 27,450 Total revenues $ 104,938 $ 91,271 $ 203,174 $ 180,516
Schedule of beginning and ending balances of accounts receivable, net of allowance	For the six months ended For the year ended June 30, 2021 December 31, 2020 (unaudited) Balance, beginning of period $ 77,159 $ 70,367 Balance, end of period 73,130 77,159 (Decrease) increase, net $ (4,029) $ 6,792
Schedule of beginning and ending balances of and changes to the allowance and the deferred allowance	For the three months ended June 30, 2021 2020 Balance Net Change Balance Net Change Allowance balance, April 1 $ (8,059) $ (7,476) Allowance balance, June 30 (9,399) (7,669) Change in allowance $ 1,340 $ 193 Deferred allowance balance, April 1 5,515 5,118 Deferred allowance balance, June 30 6,267 5,335 Change in deferred allowance (752) (217) Net amount charged to revenues $ 588 $ (24) For the six months ended June 30, 2021 2020 Balance Net Change Balance Net Change Allowance balance, January 1 $ (8,592) $ (7,515) Allowance balance, June 30 (9,399) (7,669) Change in allowance $ 807 $ 154 Deferred allowance balance, January 1 6,432 5,614 Deferred allowance balance, June 30 6,267 5,335 Change in deferred allowance 165 279 Net amount charged to revenues $ 972 $ 433
Schedule of information about the balances of and changes to deferred revenue	As of June 30, As of December 31, 2021 2020 (unaudited) Balances: Deferred revenue, current $ 210,587 $ 207,560 Deferred revenue, non-current 12,025 14,702 Total deferred revenue $ 222,612 $ 222,262 For the three months ended For the six months ended June 30, June 30, 2021 2020 2021 2020 (unaudited) (unaudited) Changes to deferred revenue: Beginning balance $ 218,133 $ 201,484 $ 222,262 $ 205,791 Additional amounts deferred 109,417 88,224 203,524 173,162 Revenues recognized (104,938) (91,271) (203,174) (180,516) Ending balance $ 222,612 $ 198,437 $ 222,612 $ 198,437
Schedule of information about the changes to contract cost balances	For the three months ended For the six months ended June 30, June 30, 2021 2020 2021 2020 Deferred commissions: (unaudited) (unaudited) Beginning balance $ 11,693 $ 10,563 $ 11,743 $ 11,196 Additions 2,135 1,630 4,193 2,694 Amortization (2,283) (1,803) (4,391) (3,500) Ending balance $ 11,545 $ 10,390 $ 11,545 $ 10,390

BUSINESS COMBINATIONS (Tables)

BUSINESS COMBINATIONS (Tables)	6 Months Ended
BUSINESS COMBINATIONS (Tables)	Jun. 30, 2021
Taxamo
BUSINESS COMBINATIONS
Schedule of purchase price	May 12, 2021 (unaudited) Cash paid to Taxamo sellers at closing $ 190,153 Fair value of acquisition holdbacks 502 Fair value of purchase commitment liability 10,034 Total $ 200,689
Schedule of purchase price to assets acquired and liabilities assumed	May 12, 2021 (unaudited) Cash and cash equivalents $ 2,441 Funds held for customers 221 Accounts receivable 7,783 Prepaid expenses and other current assets 908 Property and equipment 46 Goodwill 201,580 Accounts payable (304) Accrued expenses (6,615) Accrued compensation (3,939) Deferred other income (1,432) Total $ 200,689
Tellutax
BUSINESS COMBINATIONS
Schedule of purchase price to assets acquired and liabilities assumed	January 25, 2021 (unaudited) Capitalized Software - Developed technology $ 3,600 Goodwill 4,700 Total $ 8,300

FINANCIAL INSTRUMENTS AND FAI_2

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Tables)	Jun. 30, 2021
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS
Schedule of assets and liabilities measured at fair value on a recurring basis	Fair Value Measurements Using As of June 30, 2021 Fair Value Prices in active markets for identical assets (Level 1) Significant other observable inputs Significant unobservable inputs (Level 3) Money market funds $ 17,201 $ 17,201 $ - $ - Tellutax Contingent Consideration $ (2,276) $ - $ - $ (2,276) Fair Value Measurements Using As of December 31, 2020 Fair Value Prices in active markets for identical assets (Level 1) Significant other observable inputs Significant unobservable inputs (Level 3) Money market funds $ 265,270 $ 265,270 $ - $ -
Summary of estimated fair value of tellutax contingent consideration	June 30, 2021 January 25, 2021 Liability Fair Value Fair Value Valuation Technique Unobservable Inputs Tellutax Contingent Consideration $ (2,276) $ (2,200) Monte Carlo Simulation Revenue volatility 95.0 % Revenue discount rate 20.3 % Term (in years) 4.3
Changes in fair value of tellutax contingent consideration	Tellutax Contingent Consideration Balance, January 1, 2021 $ — Acquisition of Tellutax (2,200) Fair value adjustments (76) Foreign currency translation adjustments — Balance, June 30, 2021 $ (2,276)

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	6 Months Ended
PROPERTY AND EQUIPMENT (Tables)	Jun. 30, 2021
PROPERTY AND EQUIPMENT
Schedule of major components of property and equipment	As of June 30, As of December 31, 2021 2020 (unaudited) Leasehold improvements $ 21,017 $ 20,907 Equipment 41,485 41,410 Computer software purchased 11,684 11,620 Internal-use software developed: Cloud-based customer solutions 67,037 65,423 Internal systems and tools 28,889 25,349 Furniture and fixtures 7,679 7,674 In-process internal-use software 12,636 3,304 190,427 175,687 Less accumulated depreciation (128,816) (119,130) Property and equipment, net $ 61,611 $ 56,557
Schedule of major components of internal-use software	As of June 30, As of December 31, 2021 2020 (unaudited) Internal-use software developed $ 95,926 $ 90,772 Less accumulated depreciation (71,868) (65,090) 24,058 25,682 In-process internal-use software 12,636 3,304 Internal-use software developed, net $ 36,694 $ 28,986
Schedule of amounts capitalized for internal-use software and included in property and equipment additions on the consolidated statements of cash flows	For the six months ended June 30, For the six months ended December 31, 2021 2020 (unaudited) (unaudited) Cloud-based customer solutions $ 8,232 $ 7,731 Internal systems and tools 6,253 939 Total $ 14,485 $ 8,670

CAPITALIZED SOFTWARE (Tables)

CAPITALIZED SOFTWARE (Tables)	6 Months Ended
CAPITALIZED SOFTWARE (Tables)	Jun. 30, 2021
CAPITALIZED SOFTWARE
Schedule of major components of capitalized software	As of June 30, As of December 31, 2021 2020 (unaudited) Capitalized software $ 65,980 $ 63,071 Less accumulated amortization (38,567) (32,217) 27,413 30,854 In-process capitalized software 6,951 1,135 Capitalized software, net $ 34,364 $ 31,989

LEASES (Tables)

LEASES (Tables)	6 Months Ended
LEASES (Tables)	Jun. 30, 2021
LEASES
Schedule of company's lease assets and lease liabilities and their balance sheet location	As of June 30, Balance Sheet Location 2021 Lease assets: (unaudited) Operating lease right-of-use assets Operating lease right-of-use assets $ 22,156 Finance lease assets Property and equipment, net (Note 5) 1,070 Total lease assets $ 23,226 Lease liabilities: Current: Operating lease liabilities Current portion of operating lease liabilities $ 3,641 Finance lease liabilities Current portion of finance lease liabilities 271 Total current lease liabilities 3,912 Non-current: Operating lease liabilities Operating lease liabilities, net of current portion 26,726 Finance lease liabilities Finance lease liabilities, net of current portion 334 Total non-current lease liabilities 27,060 Total lease liabilities $ 30,972
Schedule of company's lease costs, weighted-average term and rate	For the three months ended June 30, For the six months ended June 30, 2021 2021 (unaudited) (unaudited) Operating lease cost $ 1,181 $ 2,350 Finance lease cost: Amortization of lease assets 240 463 Interest on lease liabilities 3 10 Total lease cost $ 1,424 $ 2,823 As of June 30, 2021 (unaudited) Weighted-average remaining lease term (years): Operating leases 7.0 Finance leases 1.5 Weighted-average discount rate: Operating leases 2.3 % Finance leases 2.3 %
Schedule of maturity of operating lease liabilities	Operating Leases Finance Leases (unaudited) Remainder of 2021 (six months remaining) $ 2,810 $ 269 2022 4,542 289 2023 4,460 60 2024 4,464 10 2025 4,382 — Thereafter 12,531 — Total lease payments 33,189 628 Less: Imputed interest (2,822) (23) Present value of lease liabilities $ 30,367 $ 605
Schedule of maturity of finance lease liabilities	Operating Leases Finance Leases (unaudited) Remainder of 2021 (six months remaining) $ 2,810 $ 269 2022 4,542 289 2023 4,460 60 2024 4,464 10 2025 4,382 — Thereafter 12,531 — Total lease payments 33,189 628 Less: Imputed interest (2,822) (23) Present value of lease liabilities $ 30,367 $ 605
Schedule of maturity of operating leases under ASU 840	As of December 31, 2020 Operating Leases Capital Leases 2021 $ 5,442 $ 915 2022 4,518 230 2023 4,459 — 2024 4,464 — 2025 4,382 — Thereafter 12,531 — Total Lease Payments $ 35,796 1,145 Less amount representing interest (38) Present value of minimum lease payments 1,107 Less current portion (882) Capital lease obligations, net of current portion $ 225

GOODWILL AND OTHER INTANGIBLE_2

GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)	6 Months Ended
GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)	Jun. 30, 2021
GOODWILL AND OTHER INTANGIBLE ASSETS
Changes in the carrying amount of goodwill	As of June 30, As of December 31, 2021 2020 (unaudited) Goodwill $ 218,184 $ 16,329 Other intangible assets, net 2,167 2,382 $ 220,818 $ 18,711 Balance, January 1, 2021 $ 16,329 Acquisition of Taxamo 201,580 Acquisition of Tellutax 4,700 Foreign currency translation adjustments (4,425) Balance, June 30, 2021, gross 218,184 Accumulated impairment losses — Balance, June 30, 2021, net $ 218,184
Schedule of acquired intangible assets	As of June 30, As of December 31, 2021 2020 (unaudited) Other intangible assets Weighted average amortization period (years) 5.5 5.5 Gross value $ 2,952 $ 2,825 Accumulated amortization (785) (443) Carrying value $ 2,167 $ 2,382
Schedule of future amortization expense	For the three months ended June 30, 2021 Cost of Revenues, Software Subscriptions Selling and Amortization of acquired intangible assets $ 66 $ 86 152 For the six months ended June 30, 2021 Cost of Revenues, Software Subscriptions Selling and Amortization of acquired intangible assets $ 127 $ 170 297

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	6 Months Ended
EARNINGS PER SHARE (Tables)	Jun. 30, 2021
EARNINGS PER SHARE
Schedule of earnings per share basic and diluted	For the three months ended For the six months ended June 30, June 30, Class A common stock: 2021 2020 2021 2020 (unaudited) (unaudited) Numerator, basic: Net income (loss) attributable to all stockholders $ 808 $ (29,075) $ 3,096 $ (58,139) Class A common stock as a percentage of total shares outstanding, basic 1 23.54 % 0.11 % 13.08 % 0.03 % Net income (loss) attributable to Class A stockholders, basic 1 $ 190 $ (32) $ 644 $ (16) Numerator, diluted: Net income (loss) attributable to all stockholders $ 808 $ (29,075) $ 3,096 $ (58,139) Class A common stock as a percentage of total shares outstanding, diluted 1 28.37 % 0.11 % 26.20 % 0.03 % Net income (loss) attributable to Class A stockholders, diluted 1 $ 229 $ (32) $ 811 $ (16) Denominator, basic and diluted: Weighted average Class A common stock, basic 1 34,726 132 30,592 66 Dilutive effect of common stock equivalents 2 9,985 — 10,765 — Weighted average Class A common stock, diluted 1 44,711 132 41,357 66 Net income (loss) per Class A share, basic 1 $ 0.01 $ (0.24) $ 0.02 $ (0.24) Net income (loss) per Class A share, diluted 1 $ 0.01 $ (0.24) $ 0.02 $ (0.24) For the three months ended For the six months ended June 30, June 30, Class B common stock: 2021 2020 2021 2020 (unaudited) (unaudited) Numerator, basic: Net income (loss) attributable to all stockholders $ 808 $ (29,075) $ 3,096 $ (58,139) Class B common stock as a percentage of total shares outstanding, basic 1 76.46 % 99.89 % 79.20 % 99.97 % Net income (loss) attributable to Class B stockholders, basic 1 $ 618 $ (29,043) $ 2,452 $ (58,123) Numerator, diluted: Net income (loss) attributable to all stockholders $ 808 $ (29,075) $ 3,096 $ (58,139) Class B common stock as a percentage of total shares outstanding, diluted 1 71.63 % 99.89 % 73.80 % 99.97 % Net income (loss) attributable to Class B stockholders, diluted 1 $ 579 $ (29,043) $ 2,285 $ (58,123) Denominator, basic and diluted: Weighted average Class B common stock, basic 1 112,804 120,417 116,460 120,417 Dilutive effect of common stock equivalents 1 — — — — Weighted average Class B common stock, diluted 1 112,804 120,417 116,460 120,417 Net income (loss) per Class B share, basic 1 $ 0.01 $ (0.24) $ 0.02 $ (0.48) Net income (loss) per Class B share, diluted 1 $ 0.01 $ (0.24) $ 0.02 $ (0.48)

STOCK-BASED AWARD PLANS (Tables

STOCK-BASED AWARD PLANS (Tables)	6 Months Ended
STOCK-BASED AWARD PLANS (Tables)	Jun. 30, 2021
Compensation plans:
Schedule of ESPP valuation assumptions	Previous Current Offering Period Offering Period Fair market value of common stock $ 25.83 $ 19.89 Volatility 35.10 % 35.10 % Expected term (years) 0.50 0.50 Expected dividend yield — % — % Risk-free interest rate 0.12 % 0.12 %
Schedule of stock-based compensation cost related to incentive awards	For the three months ended For the six months ended June 30, June 30, 2021 2020 2021 2020 Stock-based compensation expense: SARs and Converted SARs $ 3,520 $ 41,676 $ 6,911 $ 76,596 Stock options 393 — 770 — RSUs 793 — 1,229 — RSAs 1,446 — 3,655 — ESPP 133 — 263 — Total stock-based compensation expense $ 6,285 $ 41,676 $ 12,828 $ 76,596
Schedule of stock based compensation cost in consolidated statement of operations	For the three months ended For the six months ended June 30, June 30, 2021 2020 2021 2020 Stock-based compensation expense: Cost of revenues, software subscriptions $ 572 $ 4,168 $ 1,132 $ 7,660 Cost of revenues, services 622 6,251 1,216 11,489 Research and development 571 4,168 1,132 7,660 Selling and marketing 1,433 8,335 2,720 15,319 General and administrative 3,087 18,754 6,628 34,468 Total stock-based compensation expense $ 6,285 $ 41,676 $ 12,828 $ 76,596
2020 Plan
Compensation plans:
Schedule of Option activity	Weighted Weighted Average Average Remaining Aggregate Exercise Contractual Intrinsic 2020 Plan Option Activity Units Price Life (Years) Value Outstanding at January 1, 2021 11,876 $ 2.44 Granted 263 $ 31.51 Forfeited (281) $ 3.50 Exercised (1,677) $ 2.14 $ 35,882 2020 Plan options outstanding at June 30, 2021 10,181 $ 3.21 5.11 $ 190,675 2020 Plan options exercisable at June 30, 2021 5,895 $ 1.77 3.36 $ 118,920
Schedule of outstanding, vested and exercisable	Options Outstanding Options Vested and Exercisable Weighted Weighted Average Average Exercise Prices Units Life (Years) Units Life (Years) $0.15 to $0.71 2,234 * 2,234 — $2.15 548 3.61 548 3.61 $2.50 2,431 4.99 1,801 4.86 $2.67 650 5.68 273 5.69 $3.17 1,415 6.78 665 6.76 $3.73 1,957 8.31 371 8.01 $4.70 683 8.61 — — $17.66 12 9.87 — — $32.16 251 9.67 3 9.67 10,181 5,895 *Amended Options have indefinite contractual lives
Schedule of valuation assumptions	Option Valuation Period Q1 2021 Q2 2021 Fair market value of common stock $ 32.16 $ 17.66 Volatility 36.8 % 36.8 % Expected term (years) 6.0 6.0 Expected dividend yield — % — % Risk-free interest rate 0.4 % 0.4 %
Restricted Stock Units
Compensation plans:
Schedule of restricted activity	Weighted Average Grant Date Fair Units Value Per Share Outstanding at January 1, 2021 101 $ 23.80 Granted 352 30.73 Vested (7) 34.78 Forfeited (15) 28.86 Outstanding at June 30, 2021 431 $ 29.50
Restricted Stock Awards
Compensation plans:
Schedule of restricted activity	Weighted Average Grant Date Fair Units Value Per Share Outstanding at January 1, 2021 670 $ 19.00 Granted 59 17.66 Vested (234) 19.00 Forfeited (18) 19.00 Outstanding at June 30, 2021 477 $ 18.90

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Basis of Consolidation (Details)	May 12, 2021	Jan. 07, 2020
Taxamo
Summary of significant accounting policies
Interest acquired (as a percent)	95.00%
Systax
Summary of significant accounting policies
Interest acquired (as a percent)		60.00%

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Segments (Details) - segment	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment information:
Operating segments			1
Revenue \| Geographic Concentration Risk \| Outside United States
Segment information:
Risk percentage	7.00%	3.00%	6.00%	3.00%

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Useful life (Details)	6 Months Ended
	Jun. 30, 2021
Internal-Use Software \| Minimum
Property and equipment
Estimated useful lives (in years)	3 years
Internal-Use Software \| Maximum
Property and equipment
Estimated useful lives (in years)	5 years
Software developed for sale \| Minimum
Property and equipment
Estimated useful lives (in years)	3 years
Software developed for sale \| Maximum
Property and equipment
Estimated useful lives (in years)	5 years

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Stock-Based Compensation (Details)	6 Months Ended
	Jun. 30, 2021
ESPP
Compensation plans:
Discount	15.00%

SUMMARY OF SIGNIFICANT ACCOUN_8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenue Recognition (Details)	6 Months Ended
	Jun. 30, 2021
Deferred revenue recognition:
Payment terms (in days)	30-days
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-06-30
Deferred revenue recognition:
Revenue recognition period	3 years

SUMMARY OF SIGNIFICANT ACCOUN_9

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Cash paid for Interest	$ 119	$ 1,360
Cash paid for income taxes, net of refunds	966	490
Operating cash flows from operating leases	2,701
Non-cash investing and financing activities:
Purchase commitment and contingent consideration liabilities	12,736	14,344
Remeasurement of options for redeemable shares		$ 29,879
Leased assets obtained in exchange for new finance lease liabilities	$ 173

SUMMARY OF SIGNIFICANT ACCOU_10

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Jun. 30, 2021	Dec. 31, 2020
Recently issued accounting pronouncements
Lease, Practical Expedients, Package [true false]	true
Operating lease right-of-use assets		$ 22,156
Operating lease liabilities		30,367
Retained earnings		$ 25,530	$ 21,926
ASC 842
Recently issued accounting pronouncements
Operating lease right-of-use assets	$ 24,004
Operating lease liabilities	32,562
Retained earnings	$ 508

REVENUE RECOGNITION - Disaggreg

REVENUE RECOGNITION - Disaggregation of revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of revenue:
Revenues	$ 104,938	$ 91,271	$ 203,174	$ 180,516
Software subscriptions
Disaggregation of revenue:
Revenues	89,604	77,306	172,884	153,066
Software licenses
Disaggregation of revenue:
Revenues	57,525	57,194	113,875	113,919
Cloud subscriptions
Disaggregation of revenue:
Revenues	32,079	20,112	59,009	39,147
Services
Disaggregation of revenue:
Revenues	$ 15,334	$ 13,965	$ 30,290	$ 27,450

REVENUE RECOGNITION - Accounts

REVENUE RECOGNITION - Accounts receivable, net (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
REVENUE RECOGNITION
Allowance for accounts receivable	$ 9,399	$ 8,592	$ 8,059	$ 7,669	$ 7,476	$ 7,515
Allowance for credit loss
Balance, beginning of period	77,159	70,367
Balance, end of period	73,130	77,159
(Decrease) increase, net	$ (4,029)	$ 6,792

REVENUE RECOGNITION - Allowance

REVENUE RECOGNITION - Allowance and deferred allowance (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Allowance for credit loss
Beginning balance	$ (8,059)	$ (7,476)	$ (8,592)	$ (7,515)
Ending balance	(9,399)	(7,669)	(9,399)	(7,669)
Change in allowance	1,340	193	807	154
Deferred beginning balance	5,515	5,118	6,432	5,614
Deferred ending balance	6,267	5,335	6,267	5,335
Change in deferred allowance	(752)	(217)	165	279
Net amount charged to revenues	$ 588	$ (24)	$ 972	$ 433

REVENUE RECOGNITION - Deferred

REVENUE RECOGNITION - Deferred revenue (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
REVENUE RECOGNITION
Deferred revenue, current	$ 210,587		$ 207,560
Deferred revenue, non-current	12,025		14,702
Total deferred revenue	$ 222,612	$ 218,133	$ 222,262	$ 198,437	$ 201,484	$ 205,791

REVENUE RECOGNITION - Changes t

REVENUE RECOGNITION - Changes to deferred revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
REVENUE RECOGNITION
Beginning balance	$ 218,133	$ 201,484	$ 222,262	$ 205,791
Additional amounts deferred	109,417	88,224	203,524	173,162
Revenues recognized	(104,938)	(91,271)	(203,174)	(180,516)
Ending balance	$ 222,612	$ 198,437	$ 222,612	$ 198,437

REVENUE RECOGNITION - Contract

REVENUE RECOGNITION - Contract cost balances (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Changes to deferred commissions:
Beginning balance	$ 11,693	$ 10,563	$ 11,743	$ 11,196
Additions	2,135	1,630	4,193	2,694
Amortization	(2,283)	(1,803)	(4,391)	(3,500)
Ending balance	$ 11,545	$ 10,390	11,545	$ 10,390
Impairment loss			$ 0
Contract costs, amortization period	3 years		3 years

BUSINESS COMBINATIONS (Details)

BUSINESS COMBINATIONS (Details) $ in Thousands	May 12, 2021USD ($)	Jan. 25, 2021USD ($)payment	Jan. 07, 2020USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2021USD ($)segment	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)
BUSINESS COMBINATIONS
Cash consideration, net					$ 193,591	$ 12,318
Number of Operating Segments \| segment					1
Additional equity interests acquired					5.00%
Payments for purchase commitment liability					$ 788
Taxamo
BUSINESS COMBINATIONS
Interest acquired (as a percent)	95.00%
Cash paid to Taxamo sellers at closing	$ 190,153
Fair value of acquisition holdbacks	502
Fair value of purchase commitment liability	10,034
Purchase price	200,689
Cash received in the acquisition	2,662
Cash consideration, net	$ 187,491
Percentage of remaining outstanding share of the acquiree	5.00%
Taxamo \| Other operating expense, net
BUSINESS COMBINATIONS
Transaction costs				$ 4,522	4,522
Tellutax
BUSINESS COMBINATIONS
Purchase price		$ 8,300
Cash consideration, net		6,100
Contingent consideration		$ 2,200
Number of potential earnout payments \| payment		3
Revenue achievement period		30 months
Earn out payment for applicable measurement period		$ 0
Maximum limit on earnout payments		$ 0
Systax
BUSINESS COMBINATIONS
Interest acquired (as a percent)			60.00%
Cash paid to Taxamo sellers at closing			$ 12,374
Purchase commitment liability			$ 12,592				$ 9,750
Adjustment due to currency exchange rates fluctuation					$ 0
Additional equity interests acquired					65.00%
Payments for purchase commitment liability					$ 9,334
Systax \| Quotaholders
BUSINESS COMBINATIONS
Ownership (as a percent)			40.00%

BUSINESS COMBINATIONS - Net ass

BUSINESS COMBINATIONS - Net assets and liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	May 12, 2021	Jan. 25, 2021	Dec. 31, 2020
BUSINESS COMBINATIONS
Goodwill	$ 218,184			$ 16,329
Taxamo
BUSINESS COMBINATIONS
Cash and cash equivalents		$ 2,441
Funds held for customers		221
Accounts receivable		7,783
Prepaid expenses and other current assets		908
Property and equipment		46
Goodwill		201,580
Accounts payable		(304)
Accrued expenses		(6,615)
Accrued compensation		(3,939)
Deferred other income		(1,432)
Total		$ 200,689
Tellutax
BUSINESS COMBINATIONS
Capitalized Software - Developed technology			$ 3,600
Goodwill			4,700
Total			$ 8,300

FINANCIAL INSTRUMENTS AND FAI_3

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Details) $ in Thousands	Jan. 25, 2021payment	Jun. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Money market funds		$ 17,201	$ 265,270
Tellutax Contingent Consideration		(2,276)
Prices in active markets for identical assets (Level 1) \| Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Money market funds		17,201	$ 265,270
Significant unobservable inputs (Level 3) \| Fair Value, Recurring
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Tellutax Contingent Consideration		$ (2,276)
Tellutax
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Number of potential earnout payments \| payment	3
Revenue achievement period	30 months

FINANCIAL INSTRUMENTS AND FAI_4

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Estimated fair values of Tellutax contingent consideration (Details) $ in Thousands	Jun. 30, 2021USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Tellutax contingent consideration	$ (2,276)
Revenue volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration measurement input	95
Revenue discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration measurement input	20.3
Term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration measurement input	4.3

FINANCIAL INSTRUMENTS AND FAI_5

FINANCIAL INSTRUMENTS AND FAIR VALUE - Changes in fair value of Tellutax contingent consideration (Details) - Contingent Consideration $ in Thousands	6 Months Ended
	Jun. 30, 2021USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Acquisition of Tellutax	$ (2,200)
Fair value adjustments	(76)
Balance, June 30, 2021	$ (2,276)

PROPERTY AND EQUIPMENT (Details

PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Property and equipment
Property and equipment, gross	$ 190,427	$ 175,687
Less accumulated depreciation	(128,816)	(119,130)
Property and equipment, net	61,611	56,557
Leasehold improvements
Property and equipment
Property and equipment, gross	21,017	20,907
Equipment
Property and equipment
Property and equipment, gross	41,485	41,410
Computer software purchased
Property and equipment
Property and equipment, gross	11,684	11,620
Internal-Use Software
Property and equipment
Property and equipment, gross	95,926	90,772
Less accumulated depreciation	(71,868)	(65,090)
Property and equipment, net	36,694	28,986
Cloud-based customer solutions
Property and equipment
Property and equipment, gross	67,037	65,423
Internal systems and tools
Property and equipment
Property and equipment, gross	28,889	25,349
Furniture and fixtures
Property and equipment
Property and equipment, gross	7,679	7,674
In-process internal-use software
Property and equipment
Property and equipment, gross	$ 12,636	$ 3,304

PROPERTY AND EQUIPMENT - Additi

PROPERTY AND EQUIPMENT - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Property and equipment
Finance lease amortization	$ 240		$ 463
Property and equipment	61,611		61,611		$ 56,557
Accumulated depreciation	128,816		128,816		119,130
Excluding internal-use software and capital leases
Property and equipment
Depreciation expense	1,902	$ 1,773	3,808	$ 3,948
Assets under finance leases
Property and equipment
Property and equipment	1,070		1,070
Accumulated depreciation	464		464
Assets under capital leases
Property and equipment
Finance lease amortization	240		464	335
Property and equipment					1,360
Accumulated depreciation					1,370
Depreciation expense		167
Internal systems and tools
Property and equipment
Depreciation expense	736	565	1,433	1,091
Internal-Use Software
Property and equipment
Property and equipment	36,694		36,694		28,986
Accumulated depreciation	71,868		71,868		$ 65,090
Depreciation expense	$ 2,669	$ 2,453	$ 5,345	$ 4,464

PROPERTY AND EQUIPMENT - Major

PROPERTY AND EQUIPMENT - Major components of internal-use software (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Property and equipment
Property and equipment, gross	$ 190,427	$ 175,687
Less accumulated depreciation	(128,816)	(119,130)
Property and equipment	61,611	56,557
Internal-Use Software
Property and equipment
Property and equipment, gross	95,926	90,772
Less accumulated depreciation	(71,868)	(65,090)
Property and equipment, net excluding in-process internal-use software	24,058	25,682
Property and equipment	36,694	28,986
In-process internal-use software
Property and equipment
Property and equipment, gross	$ 12,636	$ 3,304

PROPERTY AND EQUIPMENT - Amount

PROPERTY AND EQUIPMENT - Amounts capitalized for internal-use software and included in property and equipment additions on the consolidated statements of cash flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Property and equipment
Capitalized internal-use software	$ 15,888	$ 10,565
Internal-Use Software
Property and equipment
Capitalized internal-use software	14,485	8,670
Cloud-based customer solutions
Property and equipment
Capitalized internal-use software	8,232	7,731
Internal systems and tools
Property and equipment
Capitalized internal-use software	$ 6,253	$ 939

CAPITALIZED SOFTWARE (Details)

CAPITALIZED SOFTWARE (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
CAPITALIZED SOFTWARE (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Capitalized software, bgn
Capitalized software, net	$ 34,364		$ 34,364		$ 31,989
Capitalized software additions			3,600
Capitalized software amortization expense	3,182	$ 3,022	6,350	$ 5,578
Software
Capitalized software, bgn
Capitalized software, gross	65,980		65,980		63,071
Less accumulated amortization	(38,567)		(38,567)		(32,217)
Capitalized software, net	27,413		27,413		30,854
Capitalized development costs	2,904	$ 3,558	8,725	$ 7,264
In-process internal-use software
Capitalized software, bgn
Capitalized software, gross	$ 6,951		$ 6,951		$ 1,135

LEASES (Details)

LEASES (Details)	6 Months Ended
LEASES (Details)	Jun. 30, 2021
Maximum
Remaining lease term (in years)	8 years

LEASES - Lease Assets and Liabi

LEASES - Lease Assets and Liabilities (Details) $ in Thousands	Jun. 30, 2021USD ($)
Lease assets:
Operating lease right-of-use assets	$ 22,156
Finance lease assets	$ 1,070
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, Plant and Equipment, Net
Total lease assets	$ 23,226
Current:
Operating lease liabilities	3,641
Finance lease liabilities	271
Total current lease liabilities	3,912
Non-current:
Operating lease liabilities, non-current	26,726
Finance lease liabilities, non-current	334
Total non-current lease liabilities	27,060
Total lease liabilities	$ 30,972

LEASES - Lease Costs, Weighted

LEASES - Lease Costs, Weighted Average Term and Rates (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021USD ($)	Jun. 30, 2021USD ($)
Lease Cost, Weighted average term and discount rate:
Operating lease cost	$ 1,181	$ 2,350
Amortization of lease assets	240	463
Interest on lease liabilities	3	10
Total lease cost	$ 1,424	$ 2,823
Operating leases, weighted-average remaining lease term (in years)	7 years	7 years
Finance leases, weighted-average remaining lease term (in years)	1 year 6 months	1 year 6 months
Operating leases, weighted-average discount rate	2.30%	2.30%
Finance leases, weighted-average discount rate	2.30%	2.30%

LEASES - Future Maturity of Lea

LEASES - Future Maturity of Lease Liabilities (Details) $ in Thousands	Jun. 30, 2021USD ($)
Operating Leases
Remainder of 2021 (six months remaining)	$ 2,810
2022	4,542
2023	4,460
2024	4,464
2025	4,382
Thereafter	12,531
Total lease payments	33,189
Less: Imputed Interest	(2,822)
Present value of lease liabilities	30,367
Finance Leases
Remainder of 2021 (nine months remaining)	269
2022	289
2023	60
2024	10
Total lease payments	628
Less: Imputed Interest	(23)
Present value of lease liabilities	$ 605

LEASES - Future Maturity of L_2

LEASES - Future Maturity of Lease Liabilities under ASU 840 (Details) $ in Thousands	Dec. 31, 2020USD ($)
Operating Leases
2021	$ 5,442
2022	4,518
2023	4,459
2024	4,464
2025	4,382
Thereafter	12,531
Total Lease Payments	35,796
Capital Leases
2021	915
2022	230
Total Lease Payments	1,145
Less amount representing interest	(38)
Present value of minimum lease payments	1,107
Less current portion	(882)
Capital lease obligations, net of current portion	$ 225

GOODWILL AND OTHER INTANGIBLE_3

GOODWILL AND OTHER INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
GOODWILL AND OTHER INTANGIBLE ASSETS
Goodwill.	$ 218,184	$ 16,329
Other intangible assets, net	2,167	2,382
Goodwill and other intangible assets	$ 220,818	$ 18,711

GOODWILL AND OTHER INTANGIBLE_4

GOODWILL AND OTHER INTANGIBLE ASSETS - Changes (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021USD ($)
Balance, January 1, 2021	$ 16,329
Foreign currency translation adjustments	(4,425)
Balance, June 30, 2021, gross	218,184
Balance, June 30, 2021, net	218,184
Taxamo
Acquisition	201,580
Tellutax
Acquisition	$ 4,700

GOODWILL AND OTHER INTANGIBLE_5

GOODWILL AND OTHER INTANGIBLE ASSETS - Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Other intangible assets
Carrying Value	$ 2,167	$ 2,167	$ 2,382
Amortization of acquired intangible assets
Amortization	152	297
Cost of Revenues
Amortization of acquired intangible assets
Amortization	66	127
Selling and marketing
Amortization of acquired intangible assets
Amortization	86	$ 170
Other intangible assets
Other intangible assets
Weighted Average Amortization Period (Years)		5 years 6 months	5 years 6 months
Gross Value	2,952	$ 2,952	$ 2,825
Accumulated Amortization	(785)	(785)	(443)
Carrying Value	$ 2,167	$ 2,167	$ 2,382

DEBT - Credit Agreement (Detail

DEBT - Credit Agreement (Details) - USD ($) $ in Thousands	Jul. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Apr. 03, 2020
Debt
Principal payments on long-term debt			$ 51,009
Base rate
Debt
Interest rate		3.25%
LIBOR
Debt
Interest rate		2.00%
Term Loan
Debt
Face amount					$ 175,000
Principal payments on long-term debt	$ 175,000
Line of Credit
Debt
Line of credit, capacity					$ 100,000
Line of credit, outstanding borrowings		$ 0		$ 0
In covenant compliance		True

STOCKHOLDERS EQUITY (Details)

STOCKHOLDERS EQUITY (Details) - USD ($)	Jun. 30, 2021	Jul. 28, 2020	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Common Stock
Forward Stock Split		three-for-one
Stock split							0.33
Treasury stock	0		0				0		0
Liquidation preferences		$ 0			$ 0			$ 0
Common Stock, Shares Authorized		450,000,000
Common stock par value (in dollars per share)		$ 0.001
Preferred Stock, Shares Authorized	30,000,000	30,000,000	30,000,000				30,000,000		30,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001	$ 0.001				$ 0.001		$ 0.001
Proceeds from exercise of stock option							$ 391,000	$ 52,000
Distributions					$ 123,185,000	$ 4,010,000
Distributions per share					$ 1.02	$ 0.03
Period with in the company is required settle any remaining liability for taxes to the former S-corporation shareholders	15 days
Exchange of shares			12,100,000				12,100,000
Former Class A
Common Stock
Common Stock, Shares, Outstanding					147,000			147,000
Former Class A \| Family
Common Stock
Common Stock, Shares, Outstanding					147,000			147,000
Former Class A \| Restricted Stock Awards
Common Stock
Common Stock, Shares, Outstanding	234,000		234,000				234,000
Former Class B
Common Stock
Common Stock, Shares, Outstanding					120,443,000			120,443,000
Proceeds from exercise of stock option								$ 53,000
Former Class B \| Selling stockholders
Common Stock
Common Stock, Shares, Outstanding					173,000			173,000
Class A
Common Stock
Common Stock, Shares, Outstanding	39,828,000		39,828,000				39,828,000		26,327,000
Common Stock, Shares Authorized	300,000,000	300,000,000	300,000,000				300,000,000		300,000,000
Common stock par value (in dollars per share)	$ 0.001		$ 0.001				$ 0.001		$ 0.001
Common Stock, Voting Rights		one
Class A \| Selling stockholders
Common Stock
Auto exercised options in connection with offering shares issued			640,000				462,000
Shares exchanged in lieu			356,000				219,000
Class A \| Restricted Stock Units
Common Stock
Shares issued in connection with vesting of RSUs				5			5
Shares returned in lieu of payment of taxes				1			1
Class B
Common Stock
Common Stock, Shares, Outstanding	108,017,000		108,017,000				108,017,000		120,117,000
Common Stock, Shares Authorized	150,000,000	150,000,000	150,000,000				150,000,000		150,000,000
Common stock par value (in dollars per share)	$ 0.001		$ 0.001				$ 0.001		$ 0.001
Common Stock, Voting Rights		ten
Class B \| Family
Common Stock
Common Stock, Shares, Outstanding					120,270,000			120,270,000
Common Stock
Common Stock
Common Stock, Shares, Outstanding		120,590,000
Share exchange, amount		$ 0
S Corporation
Common Stock
Amount of estimated dividends liability	$ 2,700,000		$ 2,700,000				$ 2,700,000

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income (loss) attributable to all stockholders	$ 808	$ 2,288	$ (29,075)	$ (29,064)	$ 3,096	$ (58,139)
Denominator:
Anti-dilutive shares	251		3,653		168	3,693
Class A
Numerator:
Common stock as a percentage of total shares outstanding, basic	23.54%		0.11%		13.08%	0.03%
Net income (loss) attributable to stockholders, basic	$ 190		$ (32)		$ 644	$ (16)
Common stock as a percentage of total shares outstanding, diluted	28.37%		0.11%		26.20%	0.03%
Net income (loss) attributable to stockholders, diluted	$ 229		$ (32)		$ 811	$ (16)
Denominator:
Weighted average common stock, basic (in shares)	34,726		132		30,592	66
Dilutive effect of common stock equivalents	9,985				10,765
Weighted average common stock, diluted (in shares)	44,711		132		41,357	66
Net income (loss) per share, basic (in dollars per share)	$ 0.01		$ (0.24)		$ 0.02	$ (0.24)
Net income (loss) per share, diluted	$ 0.01		$ (0.24)		$ 0.02	$ (0.24)
Class B
Numerator:
Common stock as a percentage of total shares outstanding, basic	76.46%		99.89%		79.20%	99.97%
Net income (loss) attributable to stockholders, basic	$ 618		$ (29,043)		$ 2,452	$ (58,123)
Common stock as a percentage of total shares outstanding, diluted	71.63%		99.89%		73.80%	99.97%
Net income (loss) attributable to stockholders, diluted	$ 579		$ (29,043)		$ 2,285	$ (58,123)
Denominator:
Weighted average common stock, basic (in shares)	112,804		120,417		116,460	120,417
Weighted average common stock, diluted (in shares)	112,804		120,417		116,460	120,417
Net income (loss) per share, basic (in dollars per share)	$ 0.01		$ (0.24)		$ 0.02	$ (0.48)
Net income (loss) per share, diluted	$ 0.01		$ (0.24)		$ 0.02	$ (0.48)

STOCK-BASED AWARD PLANS - Stock

STOCK-BASED AWARD PLANS - Stock-Based Award Plans (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Compensation plans:
Accrued salaries and benefits	$ 22,994	$ 17,326
ESPP
Compensation plans:
Offering Period	6 months
Accrued salaries and benefits	$ 152

STOCK-BASED AWARD PLANS - 2020

STOCK-BASED AWARD PLANS - 2020 Plan (Details) shares in Thousands	Jun. 30, 2021shares
2020 Plan
Compensation plans:
Shares authorized	854

STOCK-BASED AWARD PLANS - Amend

STOCK-BASED AWARD PLANS - Amended Options (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Compensation plans:
Remeasurement of options for redeemable shares				$ 29,879
Compensation expense	$ 6,285	$ 41,676	$ 12,828	76,596
Amended Options
Compensation plans:
Remeasurement of options for redeemable shares	$ 14,637		$ 29,879
Option Outstanding	3,676		3,676
Compensation expense	$ 393		$ 770	$ 0

STOCK-BASED AWARD PLANS - Optio

STOCK-BASED AWARD PLANS - Options under 2020 Plan (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Weighted Average Per Share
Compensation expense	$ 6,285		$ 41,676	$ 12,828	$ 76,596
2020 Plan
Units
Balance, Bgn		11,876		11,876
Granted	12	251		263
Forfeited				(281)
Exercised				(1,677)
Balance, End	10,181		0	10,181	0
Exercisable	5,895			5,895
Weighted Average Per Share
Balance, Bgn		$ 2.44		$ 2.44
Granted				31.51
Forfeited				3.50
Exercised				2.14
Balance, End	$ 3.21			3.21
Exercisable	$ 1.77			$ 1.77
Remaining contractual life, outstanding				5 years 1 month 9 days
Remaining contractual life, exercisable				3 years 4 months 9 days
Intrinsic value, exercised				$ 35,882
Intrinsic value, outstanding	$ 190,675			190,675
Intrinsic value, exercisable	118,920			$ 118,920
Vesting period				10 years
Compensation expense	3,913			$ 7,681
Unrecognized compensation expense	$ 25,025			$ 25,025
Unrecognized compensation expense period				3 years
2020 Plan \| Minimum
Weighted Average Per Share
Vesting period				1 year
2020 Plan \| Maximum
Weighted Average Per Share
Vesting period				4 years

STOCK-BASED AWARD PLANS - Opt_2

STOCK-BASED AWARD PLANS - Options under 2020 Plan Price Range (Details) - 2020 Plan shares in Thousands	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Options outstanding, vested and exercisable:
Options outstanding	10,181
Options vested and exercisable	5,895
$0.15 to $0.71
Options outstanding, vested and exercisable:
Exercise prices, lower range \| $ / shares	$ 0.15
Exercise prices, upper range \| $ / shares	$ 0.71
Options outstanding	2,234
Options outstanding, life	0 years
Options vested and exercisable	2,234
$2.15
Options outstanding, vested and exercisable:
Exercise prices \| $ / shares	$ 2.15
Options outstanding	548
Options outstanding, life	3 years 7 months 9 days
Options vested and exercisable	548
Options vested and exercisable, life	3 years 7 months 9 days
$2.50
Options outstanding, vested and exercisable:
Exercise prices \| $ / shares	$ 2.50
Options outstanding	2,431
Options outstanding, life	4 years 11 months 26 days
Options vested and exercisable	1,801
Options vested and exercisable, life	4 years 10 months 9 days
$2.67
Options outstanding, vested and exercisable:
Exercise prices \| $ / shares	$ 2.67
Options outstanding	650
Options outstanding, life	5 years 8 months 4 days
Options vested and exercisable	273
Options vested and exercisable, life	5 years 8 months 8 days
$3.17
Options outstanding, vested and exercisable:
Exercise prices \| $ / shares	$ 3.17
Options outstanding	1,415
Options outstanding, life	6 years 9 months 10 days
Options vested and exercisable	665
Options vested and exercisable, life	6 years 9 months 3 days
$3.73
Options outstanding, vested and exercisable:
Exercise prices \| $ / shares	$ 3.73
Options outstanding	1,957
Options outstanding, life	8 years 3 months 21 days
Options vested and exercisable	371
Options vested and exercisable, life	8 years 3 days
$4.70
Options outstanding, vested and exercisable:
Exercise prices \| $ / shares	$ 4.70
Options outstanding	683
Options outstanding, life	8 years 7 months 9 days
$17.66
Options outstanding, vested and exercisable:
Exercise prices \| $ / shares	$ 17.66
Options outstanding	12
Options outstanding, life	9 years 10 months 13 days
$32.16
Options outstanding, vested and exercisable:
Exercise prices \| $ / shares	$ 32.16
Options outstanding	251
Options outstanding, life	9 years 8 months 1 day
Options vested and exercisable	3
Options vested and exercisable, life	9 years 8 months 1 day

STOCK-BASED AWARD PLANS - Opt_3

STOCK-BASED AWARD PLANS - Options under 2020 Plan Options issued (Details) - 2020 Plan - $ / shares	3 Months Ended
	Jun. 30, 2021	Mar. 31, 2021
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair market value of common stock	$ 17.66	$ 32.16
Volatility	36.80%	36.80%
Expected term (in years)	6 years	6 years
Risk-free interest rate	0.40%	0.40%

STOCK-BASED AWARD PLANS - Restr

STOCK-BASED AWARD PLANS - Restricted Stock Units (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	May 12, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Compensation plans:
Compensation expense		$ 6,285	$ 41,676	$ 12,828	$ 76,596
Restricted Stock Units
Compensation plans:
Compensation expense		793		1,229
Unrecognized compensation cost		$ 11,108		$ 11,108
Unrecognized compensation expense period				3 years 7 months 6 days
Units
Balance, Bgn				101
Granted				352
Vested				(7)
Forfeited				(15)
Balance, End		431	0	431	0
Weighted Average Per Share
Balance, Bgn				$ 23.80
Granted				30.73
Vested		$ 34.78		34.78
Forfeited				28.86
Balance, End		$ 29.50		$ 29.50
Restricted Stock Units \| Minimum
Compensation plans:
Service requirement (in years)				1 year
Restricted Stock Units \| Maximum
Compensation plans:
Service requirement (in years)				4 years
PSU
Compensation plans:
Compensation expense				$ 0
PSU \| Employee \| Taxamo
Compensation plans:
Shares issued	1,230
Grant date fair value	$ 21,729

STOCK-BASED AWARD PLANS - Res_2

STOCK-BASED AWARD PLANS - Restricted Stock Awards (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Jul. 28, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Weighted Average Per Share
Stock-based compensation expense				$ 12,828	$ 76,596
Compensation expense		$ 6,285	$ 41,676	$ 12,828	$ 76,596
Restricted Stock Awards
Units
Balance, Bgn				670
Granted	59
Vested				(234)
Forfeited				(18)
Balance, End		477	0	477	0
Weighted Average Per Share
Balance, Bgn				$ 19
Granted	$ 17.66
Vested		$ 19		19
Forfeited				19
Balance, End		$ 18.90		$ 18.90
Compensation expense		$ 1,446		$ 3,655
Unrecognized compensation cost		$ 5,903		$ 5,903
Unrecognized compensation expense period				2 years 2 months 12 days
Restricted Stock Awards \| Minimum
Compensation plans:
Service requirement (in years)				1 year
Restricted Stock Awards \| Maximum
Compensation plans:
Service requirement (in years)				4 years

STOCK-BASED AWARD PLANS - Emplo

STOCK-BASED AWARD PLANS - Employee Stock Purchase Plan (Details) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	May 31, 2021	Jun. 30, 2020
Compensation plans:
Compensation expense		$ 6,285	$ 41,676	$ 12,828		$ 76,596
Class A
Compensation plans:
Offering period	6 months				6 months
ESPP
Compensation plans:
Purchase price as a percent of fair value				15.00%
Reserved for issuance				1,000
Maximum issuance (as a percentage of outstanding)				1.00%
Maximum issuance (in shares)				16,000
Compensation expense		133		$ 263
Unrecognized compensation cost	$ 227	$ 227		$ 227
ESPP \| Class A
Compensation plans:
Shares purchased					60

STOCK-BASED AWARD PLANS - ESPP

STOCK-BASED AWARD PLANS - ESPP - Option-pricing model key input assumptions (Details) - ESPP - $ / shares	6 Months Ended
	Nov. 30, 2021	Jun. 30, 2021	May 31, 2021
Compensation plans:
Discount		15.00%
Offering Period		6 months
Fair Value Assumptions and Methodology
Fair market value of common stock	$ 19.89		$ 25.83
Volatility	35.10%		35.10%
Expected term (in years)	6 months		6 months
Risk-free interest rate	0.12%		0.12%

STOCK-BASED AWARD PLANS - Sto_2

STOCK-BASED AWARD PLANS - Stock based compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Allocation of costs
Compensation expense	$ 6,285	$ 41,676	$ 12,828	$ 76,596
SAR
Allocation of costs
Compensation expense	3,520	$ 41,676	6,911	76,596
Amended Options
Allocation of costs
Compensation expense	393		770	$ 0
Restricted Stock Units
Allocation of costs
Compensation expense	793		1,229
Restricted Stock Awards
Allocation of costs
Compensation expense	1,446		3,655
ESPP
Allocation of costs
Compensation expense	$ 133		$ 263

STOCK-BASED AWARD PLANS - Sto_3

STOCK-BASED AWARD PLANS - Stock based compensation, comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Allocation of costs
Compensation expense	$ 6,285	$ 41,676	$ 12,828	$ 76,596
Research and development
Allocation of costs
Compensation expense	571	4,168	1,132	7,660
Selling and marketing
Allocation of costs
Compensation expense	1,433	8,335	2,720	15,319
General and administrative
Allocation of costs
Compensation expense	3,087	18,754	6,628	34,468
Software subscriptions
Allocation of costs
Compensation expense	572	4,168	1,132	7,660
Services
Allocation of costs
Compensation expense	$ 622	$ 6,251	$ 1,216	$ 11,489